Based on field observations, the IG reported on 5 June that the initial eruption on 29 May from the SE flank of Cerro Azul issued from three fissures. Six ‘a’a lava flows up to 5 m thick flowed rapidly from a fissure near the caldera; one of the flows reached the next fissure at a lower elevation. A 1-km-long fissure in the central part of the flank emitted multiple lava flows up to 15 m thick. Activity at a third fissure at the lower flank, also about 1 km in length, produced cones and several lava flows.
On 3 June, new thermal anomalies on the SE flank detected in satellite imagery increased in intensity and migrated E in later images. Incandescence in the same area was also noted by ground observers. On 4 June an overflight confirmed the presence of a new vent. A fissure about 400-500 m long emitted lava flows that traveled towards the S coast of Isabela. Blocks were ejected about 60 m above the vents. A VAAC report indicated that an eruption plume drifted 50 km N. On 5 June, thermal anomalies were present on satellite imagery.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”