I wasn’t a big fan of the Wai O Tapu Thermal Wonderland because the sulfur smell made me sick, but the Lady Knox Geyser is really cool. We almost didn’t go to this attraction because after getting sick at the park I was afraid to go back to the area. I love the bubbling mud in the thermal areas, but if there isn’t a lot of open space to allow fresh air I just can’t handle it.
Luckily we had to go back to Rotorura to deliver our kayak to the Trademe auction winner, so we decided to stop by the Lady Knox Geyser on the way up. Admission to the geyser is included when you purchase a ticket to the Thermal Wonderland and they give you a separate ticket so you can see the geyser on another day. We had bought the ticket a month before visiting the geyser and they still accepted it.
The geyser erupts at 10:15 every day, but unlike Old Faithful it isn’t a perfectly timed natural occurrence. The geyser is natural and would erupt without human intervention, but the park gives it a little push so it erupts like clockwork.
To make the geyser explode a park attendant adds a little bit of soap to break the surface tension which causes the water to boil. I’ve actually seen this happen at home with a pot of boiling water. If you sprinkle salt into a pot that has been resting on heat at just the right moment you will see it boil as soon as the salt touches the water. I’m not going to go into the science behind this – I have vague memories of learning the ‘why’ in my high school physics class. They explain the reaction at the geyser or you can Google it.
It was really interesting how the geyser was discovered. The area was part of a prison yard and the prisoners would use the hot pool to wash their clothes. One day when a man dumped some soap into the pit it exploded! You can imagine the scene: a dozen half naked guys sitting around a small hole when water and clothes spray everywhere. After everyone dunked for cover and realized it was just a little water not a serious explosion they began to play with the geyser. Back then the geyser wasn’t built up to look like a volcano and had a much shorter spray of water. They hauled rocks to the edge of the pool and over time the sulfur and minerals in the water formed the volcano mouth you see now.
The eruption lasts for several minutes, so if you are standing around the edge you can walk around to get pictures from different angles. If you are on the first few rows, be prepared to get wet!