Sulphur Bay: Once a howling wilderness 

The peaceful Government Gardens lie on the edge of one of the most active areas of Lake Rotorua - Sulphur Bay. Although the gardens are now carefully manicured and tranquil, this area was once very wild indeed and was once deep under water. It is part of a great crater formed during a huge volcanic eruption 220,000 years ago.

 

Lake Rotorua is the oldest continuous lake in Aotearoa, New Zealand. The lake level has risen and fallen over thousands of years. You can see the shadow-lines or former lake levels around the hills.

 

You can see a large number of platform-like formations around the lake shore.   When the lake level was 80 metres higher, some 7000 years ago, geothermal waters tumbled quartz sediments from deep underground which hardened to create these sinter structures. Ancient silica springs have turned the gravel and sand into cement to form these unusual platforms.

 

The area called Te Kaunanga was important to Maori. For centuries they used its hot pools to cure ailments. They knew of the healing qualities of the mud and the plants which surrounded the lake such as kanuka and manuka.

 

Maori also used the hot pools for cooking and the hot flat rocks for drying berries. You can see the remains of baths and cooking spots scattered about the area.

 

This area of lake Rotorua is home to 30 species of birds. It is a warm place for them although there is not much food for them. They leave the area each day to find food. It’s take-aways every day for these birds!

 

Gulls are tapu to Māori.  When invading warrior Hongi Hika surrounded Mokoia Island in 1823 the squawking of gulls warned the Ngāti Whakaue people that danger was on its way.  

 

Hot pools develop when chloride water rises from deep underground and comes up through a piece of the earth's crust that is not very strong.  Fumeroles, occur when trapped boiling underground water comes out as steam or gas through a vent in the land’s surface.  The soft, soapy-feeling water of alkaline chloride pools is clear and very hot.

 

Māori used to bathe in these muddy pools, and later, so did Europeans, who travelled long distances to take a soak!  The bubbles you can see rising to the surface makes it seem as if the mud is boiling but it isn’t really; the bubbles are actually gases escaping from underground.

 

These mud pools are created when the hot water is trapped for a long time near the surface.  After a while, it starts to have a reaction with the soil around it and that causes sulphuric acid to be formed. It’s the sulphur from this water which causes Rotorua's famous rotten-egg smell!