Geothermal Environment Research: May 20

Watching one of the tutorials Klaasz put up about Cameras in Maya I learned about changing the background colour in a render. I haven’t looked into cameras too much yet so I didn’t know that you could use an image plane as the background colour. In the example the tutor uses an image plane of a cloudy sky and then when he zooms in on the scene you can see the cloudy sky through the house windows. What a cool effect and it started me thinking about my environment for my model. I took a few photos of the mud pools in Rotorua earlier this year, how about one of them as an image plane for my background? That set me to further research geothermal environments, the rocks and minerals, the plant life and the composition of mud pools and terraces.

Mud Pools at Orakei Korako [Photograph]. (n.d.). Orakei Korako Geothermal Attraction. https://www.orakeikorako.co.nz/image-gallery-orakei-korako
Bubbling Mud at Orakei Korako  [Photograph]. (n.d.). Orakei Korako Geothermal Attraction. https://www.orakeikorako.co.nz/image-gallery-orakei-korako
Bubbling Geothermal Mud Pool [Photograph]. (n.d.). Orakei Korako Geothermal Attraction. https://www.orakeikorako.co.nz/image-gallery-orakei-korako?page=2
Sinter deposits: The Golden Fleece [Photograph]. (n.d.). Orakei Korako Geothermal Attraction. https://www.orakeikorako.co.nz/image-gallery-orakei-korako?page=2

Most of the characteristics associated with Geothermal areas like the Taupo Volcanic Zone is caused by rainwater seeping through cracks in the ground meeting magma lying close to the earth’s surface, and then rising quickly back to the surface as hot water, steam and geysers. There are some really interesting, unique characteristics of geothermal areas:

Alkaline Chloride Systems: clear boiling springs of water that has recently arrived back at the earth’s surface after travelling through heated rock is weakly alkaline and has a soapy feeling. Water has a high mineral concentration from its contact with the subterranean rocks. Typical features of these alkaline chloride systems are boiling springs, geysers and sinter deposits that are caused by those springs and geysers.

Sinter Deposits: composed of almost pure silica (White colour) which is abundant in most rocks either as pure silica minerals i.e Quartz, or combined with other elements as silicate minerals. Hot water passing through fractured rocks easily dissolves silica and other chemicals, then when geothermal water ours out of a spring or a geyser it cools quickly and starts to deposit some of the dissolved silica onto the nearest ground/ rock surface.

Sinter often contains traces of impurities or micro -organisms which then produce lovely coloured forms. Some of the most common are pink from iron oxide and grey to black from iron sulphide or pyrite.

Sinter takes varied forms, can be shaped like small volcano- like cones or like rounded masses called “geyser eggs” around geyser vents, or where the water flows over sloping ground it forms beautiful terraces.

Fumaroles and Steaming Ground:

Fumaroles are steam and hot gas vents. If the steam diffuses up through the soil then steaming ground results, often producing vividly coloured rocks and soil as a result of the hot acidic gases and fluids interacting with subterranean rock producing clay minerals tinted by trace amounts of minerals. Some unusual colours include purple from cinnabar ( mercury sulfide), orange from realgar (arsenic sulfide) and yellow to grey from sulphur.

Sulphur Crystals: caused by hot gases rich in hydrogen sulfide escaping from Fumaroles contacting the atmosphere, cooling and oxidising quickly and forming yellow crystals of pure sulphur around the vents.

Mud Pools: an icon of New Zealand scenery. They form where steam and gas rise to the surface underneath pools of rainwater. These acidic gases attack the rock forming clay. The resulting clay – rich soil mixes with the pond-water to produce a muddy, steam heated slurry. Rainfall affects the appearance of Mud-pools. In dry conditions the mud is thick and sticky and small mud volcanoes may form. In high rainfall the mud becomes much more fluid and the pool may then look like dark boiling water.

Plants in geothermal areas: geothermal areas are highly acidic and toxic because of the presence of dissolved mineral components such as arsenic and mercury, and ground temperature dictates what plants can survive there. Steaming ground for example may be as hot as 97 degrees C within 5cm of the surface and no plants can survive this so the ground is bare.

Most heat tolerant plants are mosses and lichens which can survive ground temperatures of up to 70 degrees C. Clubmoss (Lycopodium cernuum) is actually a tropical moss species which thrives here due to the warm ground and steam preventing any frosts.

Prostrate Kanuka (Kunzea ericoides var. microflorum) is a low spreading variety of kanuka shrub that only grows in geothermal areas, it tolerates ground temperatures of up to 55 degrees C.”

Information copied from:

Stewart, C. (2006, June 12). Hot Springs and geothermal energy – Te Ara encyclopedia of New Zealand. Te Ara Encyclopedia of New Zealand – Te Ara Encyclopedia of New Zealand. Retrieved May 20, 2020, from https://teara.govt.nz/en/hot-springs-and-geothermal-energy
Club moss: Shirley, C. (2009). Lycopodium cernuum [Photograph]. The Hidden Forest. http://www.hiddenforest.co.nz/plants/clubmosses/lycop02.htm

“Plants able to tolerate conditions within geothermal habitats, and also in non geothermal vegetation include:

Manuka (Leptospermum scoparium subsp. scoparium),

Mingimingi (Leucopogon fasciculatus)

Monoao (Dracophyllum subulatum)

NZ Blueberry (Dianella nigra)

Ferns Nephrolepis flexuosa and Dicranopteris linearis var linearis

Another group of plants have established into geothermal sites as they mimic aspects of its usual habitats  (Given 1995); for example outside their normal latitudinal and altitudinal range. Some species are found in warmer climates outside New Zealand, but within New Zealand are only located at geothermal sites.

Examples: Ferns Thelypteris confluens and Cyclosorus interruptus and the clubmoss Lycopodiella cernua. Many of these species are frost-intolerant and conditions such as steam and heated soils protect them from these cold events.

One of the most interesting geothermal species of geothermal habitat in New Zealand is the woody shrub prostrate kanuka Kunzea ericoides var. microflora). Prostrate kanuka is of particular interest as it is endemic to New Zealand, where it is only occurs in geothermal habitats. The form of the plant varies in relation to soil temperatures, becoming shorter in stature as soil temperatures increase.”

Information copied from:

Given, D. R. (2020). Geothermal plants. New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/ecosystems/plant-communities/scrub-shrublands/geothermal/geothermal-plants/
De Lange, P. J. (2014, August 25). Geothermal kanuka [Photograph]. New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/kunzea-tenuicaulis/
Mertens, A. (2006, April 2). Geothermal systems in the Taupo/Rotorua region: Prostrate Kanuka – Kunzea ericoides. Geothermal Systems in the Taupo/Rotorua Regionhttps://geothermalsystemsnz.blogspot.com/2006/04/prostrate-kanuka-kunzea-ericoides.html
Club Moss: Mertens, A. (2006, February 28). Geothermal systems in the Taupo/Rotorua region: Geothermal plants at Karapiti – Craters of the moon. Geothermal Systems in the Taupo/Rotorua Regionhttps://geothermalsystemsnz.blogspot.com/2006/02/geothermal-plants-at-karapiti-craters.html
Mertens, A. (2006, April 2). Geothermal systems in the Taupo/Rotorua region: Volcano mountain at hell’s gate. Geothermal Systems in the Taupo/Rotorua Regionhttps://geothermalsystemsnz.blogspot.com/2006/04/volcano-mountain-at-hells-gate.html
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