Photos

Enjoy the sparkling mud.

From the photographer:
This is the beauty of seeing what we cannot see with our eyes. Those pictures are taken at a high speed (1/500) / 200mm (i.e. 300mm) of the boiling mud in a pool in the Waiotapu Thermal Reserve. This is a sequence of 4 pictures showing the formation and explosion of mud bubbles.

From the geologist:
Rotorua's geothermal field contains 1200 geothermal features which include geysers, hot springs, mud pools and fumaroles, as well as silica terraces and flats.
Ascending hot magmatic fluids mix with near-surface groundwater to form active geothermal systems with dramatic surface features such as hot springs, solfataras, fumaroles, mudpots, geysers, and hot acid lakes. These hydrothermal features are common at stratovolcanoes and young calderas and can persist for hundreds of thousands of years. Active hydrothermal systems often precipitate colorful deposits of native sulfur and other minerals.

Fumaroles, which emit mixtures of steam and other gases, are fed by conduits that pass through the water table before reaching the surface of the ground. Hydrogen sulphide (H2S), one of the typical gases issuing from fumaroles, readily oxidizes to sulphuric acid and native sulphur. This accounts for the intense chemical activity and brightly colored rocks in many thermal areas.

Hot springs occur in many thermal areas where the surface of the Earth intersects the water table. The temperature and rate of discharge of hot springs depend on factors such as the rate at which water circulates through the system of underground channel ways, the amount of heat supplied at depth, and the extent of dilution of the heated water by cool ground water near the surface.