Scientists investigating Mount Tongariro have driven around the area measuring sulphur emissions to help them determine how active the volcano is.
GNS scientists have been monitoring the mountain since Wednesday's eruption, and were due to fly around the ash plume this weekend, but the weather conditions have not been right.
GNS vulcanologist Nico Fournier says they decided instead to put gas monitoring equipment in a car and drive on the roads around the mountain.
He says it's possible to analyse how active the volcano is by finding out how much sulphur dioxide is coming from the gas plume it's emitting.
Mr Fournier says they are analysing the data on Sunday, and by Monday will have a better picture of how active the volcano is.