White Island is continuing to produce "vigorous bursts'' of mud, rock steam and gas up to 100m high and larger explosions including molten sulphur are possible, say experts.
The seismic activity, which has lasted several days, poses a greater than usual risk to visitors, said GNS Science.
Scientists monitoring the island volcano in the Bay of Plenty say the crater lake is drying out and the frequent bursts of mud, steam and gas were still vigorous.
Past monitoring of the island showed new eruptions often develop from this type of activity and small muddy lakes sometimes form in craters "as the unrest develops geysering and explosions occur through these lakes, becoming more vigorous with time''.
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A flight is being conducted today to check for any changes to gas levels since last week.
The amount of volcanic gases measured last week were similar to those measured in December and did not suggest a large eruption was imminent.
However, White Island was still at an elevated state of unrest.
The current episode of activity on New Zealand's most active volcano began in August last year, with explosions and ash emissions, followed by the appearance of a small lava dome in November.
The volcanic alert level remained at one and the aviation colour code remained at orange.