IG reported that activity at Fernandina began on 4 September with the detection of hybrid earthquakes followed by long-period events, and finally the onset of tremor at 1225 which heralded the beginning of the eruption.
Lava emerged from a circumferential fissure near the SSW rim of the caldera and flowed down the S and SW flanks (with no evidence of the flows reaching the sea).
A gas plume with low ash content rose 4 km above the crater rim and drifted W.
Flows continued to be active on 5 September but by the evening the intensity had weakened.
An eruptive plume rose about 2.5 km.
Activity decreased significantly by 6 September.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)