Masaya (Nicaragua): INETER reported ongoing strong seismic and surface activity. There here are currently two small lava lakes active contained in two pits inside the Santiago crater. Access to Masaya’s crater rim, a very popular tourist destination, was closed to the public on Saturday.
An earthquake of magnitude 3 on Friday, felt by many residents, probably accompanied the opening of the second vent in the NE section of the crater. A third vent is in the process of forming in the SE section of the crater, the latest INETER report stated.
Nevados de Chillán (Central Chile): A series of new explosions with small to moderate ash emissions occurred at the volcano during the end of last week. This activity formed a second new crater, approx. 25×30 m wide and located 50 m beneath the northeast flank of Arrau crater, as SERNAGEOMIN staff observed on an overflight on 30 January.
According to Chilean scientists, the activity is caused by phreatic (steam-driven) explosions in the shallow hydrotermal disturbances, not by fresh magma. Temperatures in the crater areas were found to be relatively low (approx 120 deg C), which supports this interpretation as well. It is likely that more explosions occur in the near future and an exclusion zone of 2 km around the crater was put in place.
Heard (Australia, Southern Indian Ocean): An eruption was observed by crew on board the CSIRO research vessel Investigator in late January. A lava flow was seen descending the NW flank of Mawson Peak:
Weak thermal anomalies were also detected on satellite data at the end of January. Whether the activity is still going on or not is impossible to determine – most of the days, the volcano is hidden beneath thick clouds preventing satellite observations.