TEMPERATURE AND DYNAMICS OF THE PYROCLASTIC DENSITY CURRENTS FROM THE MARCH 2025 PAROXYSM OF FUEGO VOLCANO, GUATEMALA
Fuego volcano in Guatemala is one of the world’s most active volcanoes, with frequent paroxysms that generate pyroclastic density currents (PDCs), hot flows of volcanic ash, blocks, and gas, which descend the volcano’s flanks, representing a dire risk to populations living near the volcano. This was seen during the volcano’s 3 June 2018 eruption in which PDCs inundated populated areas, resulting in over 1000 casualties. Over the past decades the volcano has typically produced eruptive activity multiple times per hour, with multiple larger paroxysms per year. After an unusually long period of quiescence lasting 49 days which began in January of 2025, a new paroxysm took place on March 9th, resulting in PDCs traveling up to 6 km from the volcano. In August of 2025, we sampled the remaining, still-hot deposits of the March 2025 PDCs. In order to assess the volume, dynamics, and impacts to the channel caused by the PDCs, deposits were identified and analyzed with drone flights, satellite imagery, and photogrammetric techniques, and deposits were sampled for study with granulometric and paleomagnetic methods. Paleomagnetic studies revealed maximum temperatures of clasts within the PDC deposits allowing for the analysis of relative contribution of juvenile material and previously erupted material stored on the flanks of the volcano to the overall volume of the PDCs.