© BEN FRASERHOT: Papakura Geyser at Te Whakarewarewa Valley has started shooting water up to 4m in the air.
Te Puia chief executive Tim Cossar said Papakura Geyser had continued to "bubble away" for the past 18 months - after lying dormant since 1979 - but entered a new phase of activity late this week, with constant eruptions shooting water up to 4m in the air.
"This is a hugely exciting development for Te Whakarewarewa Valley, our manuhiri [visitors] and our people - many of whom are the latest of several generations to live and work here.
"We keep a close eye on our various geothermal features to monitor any changes, and to see her suddenly start erupting is extremely exciting. We don't know how long she will continue to perform for us, but it's certainly fantastic to see it now."
GNS Science volcano information specialist Brad Scott said he was ecstatic about Papakura's new life, which was attributed to the bore closure programme in the late 1980s.
"It is early days in our scientific investigation of these developments, but the geyser has clearly entered phase two of its recovery.
In the first phase, which started 18 months ago, she attained a level of overflow and started regaining some heat, but it was not hot enough to prompt an eruption.
"Over the past 18 months she has obviously pumped out the cold water and started hitting temperatures that allow for an eruption. We will be collecting water samples to confirm any changes in the water to support these observations."
Mr Scott said Papakura had had average temperatures around mid-90C during the past 18 months, but an initial reading on Thursday of 100.9C was a significant increase.
"Papakura is not yet erupting as strongly as she was in the 1970s and '80s, but it's a great start."
Papakura Geyser and its activity can be clearly and safely seen from existing visitor pathways and viewing areas.
Comment: Last month a bore erupted in the Rotorua city centre.