Collaborative Research: Lahar dynamics and Monitoring: A multiparametric approach grounded in infrasound

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Lahars, or volcanic mud flows, produce infrasound (low-frequency acoustic energy) that can be detected from distances of many kilometers. As such, it is possible to remotely characterize these hazardous mud flows by tracking their flow positions and energetics through time. This work seeks to develop infrasound analytical tools to locate where lahars initiate, how far and fast they move, and estimate their mass flow. Toward these goals the project will deploy and maintain seismic and infrasonic instruments at Fuego Volcano (Guatemala), where lahars are common during the rainy season (April through September). Rain gauges and time lapse cameras will be installed at locations along the lahar paths to understand how lahars initiate and to validate flow characteristics through direct observation. Fuego volcano is an ideal candidate for this study because of its frequent lahars and relatively easy access and because information learned will be applicable for mitigating risks. Lessons learned at Fuego may then be applied to dozens of volcanoes in the US and around the world where lahar activity is common. The project aims to train several graduate and undergraduate students from the US and result in scientific publication. Important capacity building in Guatemala will result from the training of Guatemalan scientists and technology transfer to observatory staff. This project will improve our understanding of the seismo-acoustic source mechanisms associated with lahars, and to develop methods that can be used to track such sources and other rapid gravity-driven mass movements. Through multi-parametric observations this study will contribute to our fundamental understanding of how lahars are triggered during precipitation events and where material is incorporated along the lahar flow path. Infra-acoustic arrays and broadband seismic sensors will be deployed at Fuego Volcano (Guatemala) with the intent to remotely monitor the most frequent channels that carry lahars during the rainy season. Signal processing techniques using data from an integrated network of arrays will be used to track and quantify flow energetics. Fuego provides an ideal field site where seismo-acoustic data will be combined with contemporaneous rainfall and geomorphologic (terrain and channel slope) observations. Computer vision techniques will be used to quantify timing, mass flow, and velocities of lahars at various positions along channels. This work merges geomorphology and geophysical approaches to study hazardous lahar phenomena. Broader impacts include development of applied technology for hazard mitigation and training of both US-based and Guatemala-based students and professionals. This award is cofunded by the PredicMon of and Resilience against Extreme Events (PREEVENTS) program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.