8.30am – 5.00pm (last ticket sales are at 4:15pm) Closed Christmas Day
The Geology of Whakarewarewa
The Whakarewarewa Village is situated within the Whakarewarewa thermal area, which is, in turn, located inside the Rotorua Thermal Field. The Rotorua Thermal Field covers a surface area of 12 KM2, but extends much further underground. The city of Rotorua is located at the Southern edge of the Rotorua caldera, which was formed through ancient volcanic activity and caldera collapse.Lake Rotorua fills the centre of the volcanic depression and contains fine ash and pumice-rich sediment.Several domes have formed along the edge of the Rotorua Caldera, including Ngongotaha, Hamurana and Pukehangi.
The Whakarewarewa thermal area occurs in the Southern area of the Rotorua Geothermal Field and contains 500 hot springs, 65 geyser vents, colourful sinter terraces and vegetation unique to geothermal areas.Several NE-trending faults within the area provide permeable pathways for geothermal fluids to travel from deep underground and reach the surface, either creating bubbling hot-pools, steaming vents, or erupting geysers.
Each geyser in the Whakarewarewa area has a name, often derived from the geyser characteristics, or drawing on the names of local heroes.The most noted geyser of the region is the Pohutu Geyser, which is the largest geyser in New Zealand.The word “Pohutu” means “big splash” or “explosion” and with up to 15 eruptions per day that travel roughly 30 meters (100 feet) into the air, Pohutu has certainly earned its name.
Other surface features at the Whakarewarewa Village include acidic liquids flowing into warm muddy pools, near-boiling alkaline waters, steam and gas flows, and areas of steaming ground associated with collapsed geothermal holes.
The clear, hot (70-100 degrees C) pools of the village are generally neutral or alkaline in PH and are formed by the deep, primary geothermal reservoir.These waters ascend to the surface through faults, with very little mixing or dilution with local groundwater.This water source is saturated with silica and pale grey silica sinter typically form in aprons along the edge of these pools.
The mud pools at Whakarewarewa tend to be acidic in nature and occur away from fault areas at raised elevation.Mud pools and ponds of turbid water are formed by activity under the surface.Hydrogren sulphide gas is emitted from boiling liquids underground and mixes with oxidised meteoric ground water to produce acid sulphate waters.These acidic waters dissolve the surrounding rock, altering and degrading structures, and producing pools of mud.This process is also responsible for collapse holes, which are common at Whakarewarewa.
The powerful geothermal forces that lie beneath Whakarewarewa seem invincible, but the geothermal landscape has been under threat for years.In the last century, over-development of bores and wells for both private and commercial use has decimated the geothermal aquifer.Thankfully, conservation efforts have been put into place in recent years and, with careful management, the geothermal treasures of the Whakarewarewa region are set to continue to sustain and enchant locals and visitors alike, for many years to come.
Experience all of Whakarewarewa's geothermal wonders with our guided Village Tour.
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