Mud and rock have been thrown several tens of metres from White Island during the last few days, as the volcano remains at an elevated level of unrest, GNS says.
Early this morning, GNS Science says the continuous volcanic tremor which has been recorded during the past few weeks at White Island changed to a pattern of "intermittent tremor".
It said the volcanic tremor remains strong, and the current level of unrest means that there is a greater than usual hazard to visitors.
GNS Science said the crater lake was drying out and the "frequent bursts of mud, steam and gas are still vigorous".
"During the last few days, the bursts have thrown mud and rock several tens of metres out from the lake area. Steam and gas clouds above the volcano are often visible from the Bay of Plenty coastline," GNS Science said.
GNS Science's past monitoring of the island shows that weak ash eruptions have often followed drying out of this type of mud-filled lake.
More vigorous explosions of mud, rock and perhaps molten sulphur are possible in future with little or no warning, it said.
GNS Science said the amounts of volcanic gases measured last week were similar to those measured in December 2012, and do not suggest a large eruption is imminent.
However, both the ongoing mud bursts and the strong seismic activity indicate that White Island is still at an elevated state of unrest.
GNS Science continues to closely monitor White Island.
The Volcanic Alert Level remains at 1 and the Aviation Colour Code remains at orange.