Page   1            2

Within the forested area southeast of Whakarewarewa Village a network of signposted trails guides visitors to the scattered thermal features. Roto Kanapanapa (Green Lake) marks the southeasternmost accessible destination. According to the tour pamphlet this is a warm lake once used by a priest in a ceremony to cleanse the deceased before burial.

Along the east side of Roto Kanapanapa some mud pots show up. Usually, their activity is quite sluggish. Now and then a bubble appears on the surface and popps with a gentle plop.

Roto Opouri (Black Lake) across the trail from Roto Kanapanapa is hard to see because it is largely obscured by trees. This is not a great loss, the lake neither captivates by its colour nor by its thermal activity. In a large loop the trail runs back into the centre of Whakarewarewa Village or, on a detour, it crosses Te Roto-a-Tamaheke (The Lake of Chief Tamaheke). In contrast to Roto Opouri the larger and warmer Roto-a-Tamaheke is highly interesting from a geothermally point of view. Numerous hot springs sit within the lake or line its shore, many of them feature temperatures around the boiling point, and a few ones are even known as geysers.
Since Roto-a-Tamaheke is fed by hot springs to a significant degree, it always exhibits elevated temperatures. Depending on rainfall and thermal activity of the springs, though, in some periods the temperature is higher than in others. For example, in 2008 temperatures between 28-35 °C (82-95 °F) were measured, whereas in 2014 values ranged from 45-50 °C (113-122 °F) (S.C. Pearson-Grant, B.J. Scott, E.K. Mroczek, D.J. Graham, Rotorua Surface Feature Monitoring Data Review: 2008-2014, GNS Science Consultancy Report 2015/124).

Thanks to the effortful work of the Tuhourangi/Ngāti Wāhiao tourism promoters, visitors can cross the western section of the warm lake on a boardwalk. Extensively ascending steam clouds the distant, notched shoreline and small islands, creating a mystic atmosphere. Optimal photo conditions would prevail in the early morning, but admission of visitors did not start until 9:00 am.
In case of proceeding on the boardwalk from south to north, as we did, the first noteworthy feature (besides the lake itself, of course) shows up on the left (west) side. It is an extensive but very shallow hot spring called Pahopeke. The boardwalk runs quite exactly along the borderline between Pahopeke and Roto-a-Tamaheke. Very often Roto-a-Tamaheke overflows into the lakelet which makes it appear like a bay.

Not far from the north end of Pahopeke three transparent blue hot springs are embedded in a sinter shield. The low steam emissions and somewhat muted blue tint of the first one indicate temperatures well below boiling point.

The other two springs are deeper blue and look as if they were noticeably hotter.

A fourth blue spring lies across the boardwalk, seemingly not as hot as the springs mentioned above.

This area on the shore of Roto-a-Tamaheke is obviously a hot spot because not far north of the described blue springs further high temperature pools are to be found. One of them is of special interest. It includes a permanently spouting vent near the centre and an intermittently spouting vent close to the west rim. When both vents were active they generated so much steam that I failed to capture a picture where both fountains reached their maximum height of about 1 metre (3 feet). The play of the western vent lasted about 5 minutes, followed by a quiet phase of another 5 minutes, which added to an interval of approximately 10 minutes. Our observation period was only 30 minutes, though, so the values are not very significant.

Shortly thereafter the northwest corner of Roto-a-Tamaheke is reached, if there is such thing as a corner. Even if not, the place is occupied by further hot springs, but they lack any appealing hue.

For tourists this is the end of the exploration at Roto-a-Tamaheke, but for locals and for scientists the northern shore area beyond the springs shown on the picture above holds many further treasures. This is where Ororea (Spring up with Rumble), the most prominent geyser around the lake, is located. It was active between 1938 and 1943, and again from 1982 to 1995. Heights and intervals don't seem to be available. Since the geyser is part of a group called Ororea Springs, it is not clear if and how the other members may have contributed to the activity. Besides the Ororea Springs, this area hosts a large hot pool called Waipatuhuka and the small spring Moutere immediately west of it. Likewise not open to visitors is the eastern shore of Roto-a-Tamaheke, where according to Ashley D. Cody in 1983 the unnamed geyser S435 erupted many times a day 3–5 m (10-16 feet) high. It ceased to play because the vent was destroyed by humans.
North of Te Roto-a-Tamaheke the trail leads into an area peppered with hot springs of all sizes. Most of them contain murky-grey acid-sulphate waters and are well below boiling temperature. Rarely tourists stray into these outlying areas of Whakarewarewa, even though the trails are not closed to visitors. From there the next picture shows a last glance back across an unnamed hot spring to Roto-a-Tamaheke and the steam plume of the erupting geyser on the righthand side.

It would be too much to include all the accessible springs of this area, also because their appearance can not compete with the features listed above. There are a few exceptions, though. One of these is a large and quite hot blue lake some 50 metres north of Roto-a-Tamaheke and east of an old bathing spring called Turikotiti or Turikori.

The other exception is a geyser. It can be found on the bank of Puarenga Stream near the northern boundary of the area. We did not expect to see Okianga (could be translated as "Driving Force by an Oak") playing, since it is known as dormant since 1999. Ashley D. Cody gave an overview over Okiangas changing activity: eruptions started in 1960, and a first phase of activity with short intervals (for example 12 minutes) and heights up to 5 m (16 feet) ran until 1972. After a period of dormancy or, somewhat later, sporadical eruptions at low atmospheric pressure, regular activity resumed from the late 1980s to the late 1990s. During this period it played up to 4 m (13 feet) high every 35–60 min. (A.D. Cody, Recovery of Rotorua geothermal field, New Zealand: Progress, issues and consequences, Geothermics, 2005). From the trail Okianga is very hard to spot because it features only a small vent hidden within a field of boulders.

After a short waiting time, at least we could observe some low splashing from the vent, maybe 30-50 cm (1-2 feet) high.

Page   1            2

↑ Back to top