Science into Policy: how satellite data can support decision-making during volcanic crises around the world - a recent example from East Africa.

Globally, over 800 million people live within 100 km of a volcano.  The contrast between geological and human timescales makes it notoriously difficult to predict when and where the next eruption will occur. However, the timescales of magma ascent mean that monitoring systems can detect changes, allowing scientists to judge changing likelihoods of hazardous events, to raise (and lower) volcanic alert levels if they are in place, and advise authorities, who may in turn decide to call evacuations. Thus volcano monitoring and advice saves lives and supports economic development. Despite this, many volcanoes near large population centres have little or no ground-based monitoring meaning most alerts do not accurate reflect hazard levels. Recent developments in satellite technology and machine learning are transforming the way we study our planet, changing our perception of volcanic activity and revolutionising the ways in which volcanoes are monitored. Here, we focus on the East African Rift system, where exposure is high and ground-based monitoring is scarce.

First, we showcase how satellite data has enabled the systematic identification and characterisation of deformation at 16 otherwise unmonitored volcanoes, demonstrating a previously unrecognised, but extensive hazard. Then we discuss the scientific response to the 2024-2025 seismic crisis in the Fentale-Dofen Region, Ethiopia, which was caused by a sequence of magmatic intrusions over 6 months. UNOCHA report that 75,000 people were evacuated. The largest intrusion was ~ 50 km in length causing ~ 3 m of surface displacement and extensive surface fracturing. Satellite data and analysis provided by international organisations including the UK Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET), the ERC Grant MAST (PI Biggs) and the GVEWERS programme of the CEOS Working Group on Disasters played a critical role in informing and supporting crisis response efforts. Real-time analysis was discussed with partners at Addis Ababa University and used by the Ethiopian Scientific Advisory Committee comprising scientists from Addis Ababa University, the Geological Institute of Ethiopia and other relevant institutions to monitor the events and keep the Ethiopian Disaster Risk Management Commission (EDRMC) and the public continuously informed. The advisory committee provided a highly simplified zoned map summarising the most likely scenarios and zones of hazard. Alongside this, a series of open-access Event Response Reports was published on the COMET website to support situational awareness and decision making by international stakeholders. For example, these reports supported the British Geological Survey (BGS) International Natural Hazards Forward Look (INHFL) reports and volcano advisory assessments for the UK’s Foreign, Commonwealth and Development Office (FCDO).

This event highlights two pathways for scientists to address societal challenges, by engaging and supporting the process of decision-making. Firstly, that there is an urgent need for enhanced scientific monitoring, scientific expertise and preparedness in the East African Rift, particularly the infrastructural, and institutional capacities to support these efforts. Secondly satellite technology now provides monitoring data at sufficient spatial and temporal resolution to be used during crises, and if properly supported, could provide the foundation for global volcano monitoring systems.