This Temblor map shows recent large magnitude subduction zone earthquakes around the location of today’s M=5.6 quake. What is evident is that there have been earthquakes several hundred kilometers to the north and south of today’s event, but none in southern Ecuador. This could mean that the area has built up a significant amount of stress, which could be released in a large subduction zone earthquake, or that the geometry of the subduction zone prevents large events from happening.
Based on the reported depth from both the USGS (52 km) and the EMSC (60 km), and the thrust focal mechanism, this earthquake likely occurred on the subducting slab where the Nazca Plate slides beneath the South American. By examining the Slab 1.0 model from the USGS' Gavin Hayes (which is also visible in Temblor as 'Megathrust Zones'), the subducting slab should be between 50 and 60 km depth in the location of today's earthquake. Therefore, a minor slip event on the subduction zone is the likely cause of the quake.
Comment: Another 'mini tornado' was reported further south in the English town of Blackburn as it swept through an industrial estate.