Volcanic activity on White Island has increased significantly from early this morning though the GNS alert status remains at level 3 for now.
GNS Science says the tremor activity on the volcano has been steadily increasing since about 4am.
Volcanic gas pressure remains high on the island, where steam and mud have been jetting from craters created by the eruption on Monday.
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GNS interprets these signals as evidence of continued high gas pressures within the volcano.
The volcanic alert level remains at 3 on the 5-step scale and the aviation code remains at Orange indicating an eruption is occurring with little or no ash produced.
Duty volcanologist Craig Miller said the tremors indicated evidence of continued high gas pressures within the volcano.
"The situation remains highly uncertain as to future activity. Eruptions in the next 24 hours are still likely to occur."
Results from flights yesterday to study gas over the island still being analysed.
"These are important for understanding the processes driving the volcanic activity.
"The gas flights are conducted in the air, hundreds of metres above the volcano, and concentrations measured there may not reflect concentrations present in the crater floor.
"There is an extremely low likelihood of any potential ash affecting the mainland, but people may smell gas, depending on the prevailing wind direction. Our monitoring equipment continues to function and is providing us with continuous data on the volcano's activity."
GNS video explainer on the volcanic alert level system in New Zealand