GNS Science is reassuring hikers on the Tongariro Crossing and Mt Ngauruhoe despite a swarm of earthquakes around the mountain.
Mt Ngauruhoe Photo: 123RF
The increase in volcanic activity has caused the alert level for Mt Ngaruhoe's to be raised from 0 to 1, which means low levels of unrest.
Volcano geophysicist Art Jolly said the increase in activity over the past four days is not unusual for the mountain. He said scientists were keeping a close eye on it, but did not expect an eruption.
"We don't anticipate that the risk has changed substantially in the past week or so. In our view hikers are reasonably safe - they are as safe as they would have been probably a week or so ago or more."
The biggest and most active cone of the Tongariro volcano complex, Mt Ngauruhoe last erupted in 1975. It is located in Tongariro National Park between Mt Tongariro to the north and Mt Ruapehu to the south.
At 2291m it is the highest point of the Tongariro mountain group.