OVSICORI-UNA reported that an incandescent avalanche descended Arenal’s SW flank on 6 June producing an 800-m-long scar and depositing a wide debris fan at the base of the volcano. A plume of dust, ash, and gas drifted W and NW, depositing fine ash in a small area downwind. The plume panicked tourists and park rangers 2 km away to the W. The park was immediately closed for the day and the tourists were evacuated. According to a news article, another incandescent avalanche descended the SW flank on 10 June and generated an ash plume. Authorities evacuated people in the area.
Sources: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA), Nacion – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”