Explosive activity increases at Ecuador’s Tungurahua Volcano

August 22, 2012 – ECUADOR – Tungurahua’s eruption continues. This morning, a tall ash plume was rising to 32,000 ft (ca. 10 km) altitude and drifting west. A slight decrease in tremor is visible on the latest seismograms. So far, effects of the eruption have been limited to ash fall. In canton Quero, the ash fall during the past days has damaged more than 5000 hectares of plant cultivations and hit about 2.000 families. In the meanwhile, scientists from the volcano observatory have made an over flight of the volcano and posted the following interesting update (freely translated) for 20-21 Aug: The volcano emits a near constant eruption column, associated with explosions, that reached a maximum height of 5 km and an average height of 1.5 km above the crater, with moderate ash content, drifting to the west. There were no new reports of ash fall. An increase in the number and size of the explosions was observed since 15:00 local time on 20 Aug. Until 16:00 on 21 Aug, there were 16 large explosions producing strong cannon-shot noises heard in villages near the volcano and in cities as far away as Ambato, Riobamba and Miracle. The seismic activity at Tungurahua shows a constant tremor signal associated with steam, gas and ash emissions. Otherwise, the roaring noises have decreased in intensity and duration with respect to the previous days. In the evening observatory staff observed constant expulsion of hot material in jets. Lava blocks landed outside the crater and rolled up to 1.5 km from the top of the volcano’s flanks. An explosion at 14:11 on 21 Aug generated an ash column rising 4 km above the crater that produced a small pyroclastic flow that descended approximately 2.5 km along the Achupashal creek. Thermal images show near continuous explosive activity from the inner crater, ejecting incandescent material onto the upper flanks of the volcano, where temperatures ranged between 116 and 150°C. About 110 families living within close proximity of the volcano have been evacuated. –Volcano Discovery