No deformation was detected at Chiles-Cerro Negro between 2006 and 2009 during an ALOS surveys of Colombian volcanoes (Parks et al., 2011).
Starting in 2013, there were several seismic swarms under Chiles-Cerro Negro, which culminated in a magnitude 5.6 earthquake on Oct. 20 2014 and up to 7000 smaller events per day. InSAR observations of the event showed it to be almost purely tectonic and dip slip in nature, with a maximum surface uplift of 23 cm (Ebmeier, 2015). GPS observations show a slight uplift signal starting ~10 days before the M5.6 event, which has been attributed to either magmatic or hydrothermal fluid accumulation in a deep source ~ 15 km south of the volcanoes (Ebmeier, 2015).