All volcanoes in Papua New Guinea fall under 3 classes; Active, Potentially active (dormant) and Inactive (extinct). This classification is based on the eruptive activity of a particular volcano, whether it frequently erupts, seldom erupts, rarely erupts or hasn’t erupted in recent times but has geological records of eruptions in pre historical times. There are geological evidences that exist to support that status given to volcanoes. Below are volcano classifications and basic definitions.
Active volcano – A volcano that is currently erupting, has erupted recently and in historically recorded period (after 1850s for PNG) or has been showing signs of unrest (scientifically implied by monitoring data and physical observations). According to Smithsonian a volcano that has erupted within that last 11 700 years. Details of volcanic activity in PNG are more complete after the 1940s which marks the establishment of Rabaul Volcano Observatory. Basically, a volcano that is awake and alive.
Potentially active volcano – A volcano that has no recorded evidence of eruption within historical time but may have pre historical recorded evidence of an eruption. It has a youthful morphological appearance (Less obvious or no sharp ridges and gullies from erosion over time) but has surface fumarole and solfatara features. A volcano with these factors is likely to erupt in the future. Basically, a sleeping volcano.
Inactive volcano – A volcano that has no recorded evidence of an eruption within historical time and the last 10 000 years (pre historical period/Holocene epoch) but has geological evidence or eruptive products older than the Holocene epoch. It has no surface solfatara or fumarole features and has old morphological features showing deep valleys/gulleys with sharp ridges from a long period of surface weathering and erosion. Other inferred evidences may show a closed subsurface plumbing system and an depleted magma chamber. It’s unlikely to erupt again. Basically, a dead volcano.