The 2023‒2025 Eruption of Ebeko Volcano: Monitoring Using a Drone and a Time-Lapse Camera

The eruption activity of Ebeko Volcano on Paramushir Island, Kuriles starting in January 2022 in the Korbut Crater began to wane in August 2024, ceasing altogether on January 19, 2025. The temperature in the ash–gas columns was measured using an infrared camera from aboard a drone. Its value was 674 ± 104°C involving an uncertainty of ~33% due to absorption by ash in the measurable wavelength range, 8–14 µm. Phreatic explosions were also occurring along the periphery of the active vent during the period August 8–15, 2024 producing fissures and ditches, including those in the Middle Crater. The formation of linear/ring structures may indicate local failure due to tension caused by subsidence of the volcanic edifice after the top of the magmatic column was removed by violent explosions when fresh magma was supplied in lesser amounts or stopped altogether. A violent explosion occurred on May 25, 2025 hurling bombs to distances of 1.5 km at velocities of ∼120 m/s. The explosions of August 8, 2024 and May 25, 2025 caused the descent of several lahars that were occasionally as long as 2 km. The infrared survey from aboard the drone helped update maps of thermal anomalies on the volcano on a regular basis. Two fumarolic fields near the Korbut Crater were completely buried under pyroclastic material, while the others persisted in their limits. Areas of steam-gas discharge were added due to the activity of newly formed fissures produced by the August 2024 phreatic explosions, also at the western rim of the Middle Crater. The temperature in the Korbut Crater decreased from 500 ± 102°C in 2023–2024 down to 160 ± 40°C in June 2025.