Bay of Plenty residents may have spotted large steam and gas plumes coming from Whakaari/White Island in the past few weeks.
GNS Science volcano specialist Brad Scott said the steam and gas plumes originated from several active vents on the island and were clustered in and around the craters formed in December 2019.
Scott said several factors contributed to how the steam and gas plumes appeared above the volcano.
"These include heat flow, gas output, and the presence of groundwater, lakelets or crater lakes. Humidity, dew point, air temperature and windspeed can also play a role.
"Line all of these up like we did over the last couple of weeks and you can have large spectacular steam and gas plumes over the volcano."