Frying Pan Lake and Cathedral RocksThermal activity on the shore of Lake Rotomahana, near the former site of the Pink Terrace
The Waimangu Volcanic Rift Valley is the hydrothermal system created on 10 June 1886 by the volcanic eruption of Mount Tarawera, on the North Island of New Zealand. It encompasses Lake Rotomahana, the site of the Pink and White Terraces, as well as the location of the Waimangu Geyser, which was active from 1900 to 1904.[1][2] The area has been increasingly accessible as a tourist attraction and contains Frying Pan Lake, which is the largest hot spring in the world,[3] and the steaming and usually pale blue Inferno Crater Lake, the largest geyser-like feature in the world although the geyser itself cannot be seen since it plays at the bottom of the lake.[4]
Waimangu is a Māori-language word meaning "black water". This name comes from the water that was thrown up by the Waimangu Geyser, which was black with mud and rocks.
From the 1890s onwards, the valley has gradually been re-populated naturally by plants ranging from hot water-loving algae and bacteria to mosses and many species of native ferns, shrubs and trees. These in turn support native birdlife including kererū, tūī, shining cuckoo, fantail, bellbird, and pūkeko, as well as introduced bird species such as mynah, magpie, finch and sparrow. A population of black swan thrives in the lower parts of the valley and on Lake Rotomahana. According to local guides, these have been introduced to the region from Western Australia by George Edward Grey in the 19th century along with wallaby.
As a rare eco-system completely naturally re-established following a volcanic eruption, Waimangu is protected as a Scenic Reserve, administered by the Department of Conservation NZ. The developing local native forest is the only current New Zealand instance of vegetation re-establishing from complete devastation without any human influence such as planting.[5] Many of Waimangu's geothermal features are ranked as Category A – extremely important, of international significance.[6]
History
The largest volcanic eruption in the past 700 years in New Zealand, the 1886 Mount Tarawera eruption,[7] created the geo-thermal area of the Waimangu Volcanic Rift Valley. The valley lies at the south-western end of the 17-kilometre (11mi) rift created in this one-day eruption. All vegetation in the Waimangu Valley was completely destroyed by the eruption and the area was covered in mud and volcanic ash on average 20 metres (66ft) thick.[8]
Over the decade following the Mount Tarawera eruption, hydrothermal surface activity and geothermal features permanently established themselves in the Waimangu Valley, even though no such activity had been reported there before 1886. Plant life slowly re-established itself around the turn of the century as the new soil began to settle and stabilise.
The first significant hydrothermal feature of the area was the Waimangu Geyser, active from 1900 to 1904. Over the course of the first two decades of the 20th century, several events shaped the area around Echo Crater and Inferno Crater. Eruptions in 1915 and 1917 enlarged Echo Crater. The craters formed by the latter eruption filled up to become Frying Pan Lake by mid 1918. Further smaller eruptions continued throughout the 20th century, with the most recent one in May 1981 in the Raupo Pond Crater destroying the Mud Rift created there in 1906.[8]
Frying Pan Lake overflow stream
Geothermal and hydrothermal features
The four-kilometre (2.5mi) stretch of the Waimangu Volcanic Rift Valley running from Southern Crater to the shores of Lake Rotomahana has been a hotspot of geothermal and hydrothermal activity since the 1886 Mount Tarawera eruption, and contains the three lake-filled craters Southern Crater, Echo Crater, and Inferno Crater, as well as the bush-clad Raupo Pond Crater, Fairy Crater and Black Crater.
The 50-metre-deep (160ft) Southern Crater was formed by the 1886 Mount Tarawera eruption and has not been notably active since. Its floor is filled by the shallow two-metre-deep (6.6ft) Emerald Pool, a cold water lake of mostly rainwater. The lake's water is usually a brown colour, but can vary depending on the state of the plants growing in it. Red aquatic fern growth is sometimes present.
A short distance northeast lies Echo Crater, the biggest crater of the area, filled with the steaming-hot Frying Pan Lake, which is the largest hot spring in the world. The lake has an average depth of six metres (20ft) and covers 38,000 square metres (410,000sqft). The average temperature of its acidic (pH 3.5) water is 55°C (131°F) and the lake's overflow is the source of Waimangu Stream[9] (Hot Water Creek)[10] flowing through the valley and into Lake Rotomahana.
Colourful sinter terraces are visible on the western shore of Frying Pan Lake, and immediately east of Echo Crater was the site of the extinct Waimangu Geyser. The crater area continued to be the source of eruptions in 1915, 1917, and last in 1973, and is still highly active, as evident by the steaming Cathedral Rocks to the north, and a cluster of hot springs and silica formations northeast of the lake referred to as "Hot Springs of Mother Earth (Nga Puia o te Papa)".[10]
Bird's Nest Spring
The margins of Waimangu Stream from Frying Pan Lake to east of Inferno Crater are covered with delicate silica formations and colourful mineral deposits containing traces of arsenic, molybdenum, antimony, and tungsten, while the stream bed is home to blue-green algae and filamentous colonies of the photosynthetic bacterium Chloroflexus aurantiacus in a range of colours from bright green to orange. In the midst of this area is the picturesque Bird's Nest Terrace, a delicate silica terrace with the small volcano-shaped Bird's Nest Spring atop continuously erupting near boiling-hot water about one metre (3.3ft) high. The terrace is covered in blue-green algae, which cannot survive in the hot stream of water running down from the spring, providing a colourful contrast of green and orange.
Further along, Waimangu Stream flows past the aptly named Clamshell Spring, a hot spring of boiling silica-rich water, and then continues through a deep natural trench with walls of silica stalactite formations formed by the dripping of trickles of mineral-rich water.
Bird's nest terrace spring
North of this area, on the slope of Mt Haszard, is Inferno Crater, filled with a striking pale blue lake of highly acidic water with a pH as low as 2.2.[11] The crater was blasted into the side of the mountain as part of the 1886 Mount Tarawera eruption event and remains the site of the largest geyser-like feature in the world.[8] Although the actual geyser plays at the bottom of the lake and cannot be seen, a handful of active fumaroles are visible on the shore and the cliff face behind the lake. The water level of this up-to-30-metre-deep (98ft) lake follows a complicated rhythmic cycle that is interconnected with the nearby Frying Pan Lake.
Inferno crater at Waimangu volcanic rift
Mt. Haszard was named after school teacher Charles Haszard and members of his family who were killed during the Mount Tarawera eruption. The locally prominent small mountain contains the shallow Raupo Pond Crater, the 56-metre-deep (184ft), steep-sided Fairy Crater, and Black Crater. All of these craters were formed during the Mount Tarawera eruption and have subsequently been completely covered in native bush.
Waimangu Stream continues east past Mt Haszard and past a prominent kaolin clay slope featuring hot springs, to merge with the cold water Haumi Stream, which cools the combined water flow considerably.
Blue pool at Warbrick Terrace
Further geothermal features along the lower part of the valley include the Marble Terrace, featuring an expansive sinter flat and buttresses composed of similar material to the Pink and White Terraces, and the multi-coloured Warbrick Terrace. The white and orange silica deposits of the Marble Terrace are fed by the hot spring in Iodine Pool, with small waves of water overflowing the pool at around 97°C (207°F) temperature and washing over the terrace. Iodine Pool is named after the brown colouring of the rocks and bank around it.[10]
Warbrick Terrace at the end of the Rift Valley is named after members of the Warbrick family, who were involved in guiding tours in the area in the two decades following the 1886 Mount Tarawera eruption. The terrace is a set of fast-growing orange and white silica platforms similar to Marble Terrace. From the 1930s to the 1950s, a small geyser played on the terrace. The area in this open-sided crater features several small clearly visible hot springs and a prominent aggregation of layers forming a dam around a pale blue pool of silica-rich water. The dam started growing in the 1990s by sinter deposition that is assisted by the growth of algae and encloses an ever-deepening pond of water behind it.[12] The pond drains from time to time, revealing the delicate silica formations and edges.
Fauna and flora
Waimangu is home to a wide range of micro-organisms and plants adapted to the different thermal conditions in the valley, from thermophilic bacteria surviving temperatures of 70°C (158°F) and algae growing in acidity levels of pH 3.8[13] to mosses and prostrate kanuka growing in soil temperatures up to 55°C (131°F).[14]
All vegetation in the valley originates from no earlier than the 1890s, when plants started re-populating the area in a natural succession following the complete destruction of any plant life by the 1886 Mount Tarawera eruption. Over the past 120 years, plant life in the Waimangu Valley has re-established itself via dispersion of spores and seeds by wind and birds; no plantings by humans were done. Subsequent small eruptions still caused local disturbance of the flora, notably the 1917 Echo Crater eruption destroying much of the flora between the crater and the visitor centre.
Blue-green algae growing on the sinter floor of Waimangu Stream
The valley's botanically rich ecosystem now includes close to 50 different tree and shrub species, around 50 ferns and allied plants and many herbaceous plants and grasses.[14] Notable species include kanuka adapting a prostrate habit on account of the warm soil temperatures, arching clubmoss capable of growing in soil temperatures of over 50°C (122°F),[15] and large populations of threatened fern species. Some of the plants are frost-intolerant and are restricted to hydrothermal areas in New Zealand. Different species of bacteria, such as Chloroflexus, co-exist with blue-green algae in the beds of hot water streams in the valley, in particular the overflow stream from Frying Pan Lake. The algae and bacteria form carpets of vivid hues ranging from orange to bright green and blue depending on water temperature and sulphur concentration. The margins of these streams are often populated by mosses and ferns.
Several non-native plant species have also re-spread into the valley, as have possums, rats and mice. A pest control scheme was introduced in 2000, and efforts are underway to ensure Patiti Island in Lake Rotomahana is kept pest-free.
Tourism
The first significant tourism in the Waimangu Valley area started with the eruptions of the Waimangu Geyser in 1900. Day trip visitors from Rotorua were keen to see the geyser erupting reportedly up to 460 metres (1,510ft) high until its cessation in late 1904. A tourist trip called the "Round Trip" ran from the summer of 1902–1903.
In 1903, four people were killed by a sudden eruption of the Waimangu Geyser. Despite the dangers, the area remained a popular tourist attraction. The 1917 Echo Crater eruption destroyed a nearby accommodation building and killed two people. This event was the last major event in the valley and changed the landscape by causing Frying Pan Lake to form by mid 1918. The ruins of the accommodation building were pulled down in 1970.[16]
Waimangu's intense hydrothermal activity and diverse features make it an area of international interest for geologists, volcanologists, but also botanists with an interest in the uniquely adapted thermotolerant plants inhabiting zones across a great range of soil acidity levels and temperatures. Scientific monitoring equipment was installed at several sites in the Waimangu Valley in 1970, in particular to investigate the unusual interlinked cyclic variation between Frying Pan Lake and Crater Lake.[8]
Since 1990, tourism in the Department of Conservation-administered Scenic Reserve has been operated by Waimangu Volcanic Valley Ltd under a lease and has won several tourism and environmental awards.[17] The operation includes a courtesy shuttle bus service running along the private gravel road through the valley between the visitor centre and Lake Rotomahana, and a boat cruise on Lake Rotomahana. The bus services three bus stops where the gravel road intersects with the walking track through the valley. It provides a schedule of nine return trips per day – unlimited access to it is included in the entry fee. The boat cruise runs 5–6 scheduled trips daily and is an additional price.[10]
Amenities provided in the valley include a visitor centre, opened in 2000,[18] a cafe and gift shop, and additional toilets near the Warbrick Terrace. The visitor centre and car park are located along Waimangu Road, six kilometres (4mi) from State Highway 5, fifteen minutes drive south of Rotorua.
The main walk through the Waimangu Volcanic Rift Valley comprises 3.6 kilometres (2.2mi) of easy-walking wide gravel paths and boardwalks and is accessible via wheelchairs, except for Inferno Crater and the Mt Haszard Hiking Trail. The walk starts at the visitor centre and tends downhill past the Southern Crater, Echo Crate and Frying Pan Lake, past a number of geothermal features, the Marble Terrace and Warbrick Terrace, and finishes at Lake Rotomahana. A short detour of 50 steps leads up to a viewing platform next to Inferno Crater Lake. Due to the attractions along the way, the suggested walking time is 1.5 to 2 hours. The courtesy shuttle bus can be used to return to the visitor centre from any of the three bus stops, or to shortcut between them.
While self-guided walking is the most popular option to explore the geothermal features along the walk, fully guided tours are also available.[19] The 45 minute boat cruise takes in thermal activity along the shores of Lake Rotomahana that can only be seen from the water.
The additional Mt Haszard Hiking Trail was opened in 2005[20] and although steeper, is of walking track standard. The track follows parts of the early 1900s Waimangu "Round Trip" walking route and continues to climb up from Inferno Crater, skirting Raupo Pond Crater, Fairy Crater and Black Crater, with several good vantage points providing panoramic views over the valley. It adds 20 minutes walking time, but does not pass any notably active geothermal features. It is recommended to visit the geothermal features between Bird's Nest Terrace and the confluence of Haumi Stream and Hot Water Creek beforehand or back-track once the hiking trail re-joins the main path, to not miss out on them.
In August 2013, the Te Ara Ahi bicycle trail was completed. It encompasses Waimangu and makes it possible to ride on a dedicated bicycle path all the way from Rotorua to the Waimangu Volcanic Valley. The 30-kilometre (19mi) Rotorua-Waimangu section is a 3–4 hour easy-intermediate ride via a concrete bike path and then Waimangu Road.[21]
Related Research Articles
A geyser is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in a few places on Earth.
The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.
The Pink and White Terraces, were natural wonders of New Zealand. They were reportedly the largest silica sinter deposits on Earth. They were long thought completely destroyed in the 1886 eruption of Mount Tarawera, until evidence emerged of their continued existence. New hydrothermal features formed to the south-west i.e. Waimangu Volcanic Rift Valley.
Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fissured down the middle by an explosive basaltic eruption in 1886. While the 1886 eruption was basaltic, study has shown there was only a small basalt component to the previous recent rhyolitic predominant eruptions. This eruption was one of New Zealand's largest historical eruptions, and killed an estimated 120 people. The fissures run for about 17 kilometres (11 mi) northeast–southwest.
Te Wairoa was a village close to the shore of Lake Tarawera near Rotorua, New Zealand. The village was buried by volcanic ash in the 1886 eruption of Mount Tarawera. It was later excavated and is now open as a tourist destination, the Buried Village. The nearby Wairere Falls are also a tourist destination.
Lake Rotomahana is an 890-hectare (2,200-acre) lake in northern New Zealand, located 20 kilometres to the south-east of Rotorua. It is immediately south-west of the dormant volcano Mount Tarawera, and its geography was substantially altered by a major 1886 eruption of Mount Tarawera. Along with the mountain, it lies within the Ōkataina Caldera. It is the most recently formed larger natural lake in New Zealand, and the deepest in the Rotorua district.
Lake Tarawera is the largest of a series of lakes which surround the volcano Mount Tarawera in the North Island of New Zealand. Like the mountain, it lies within the Ōkataina Caldera. It is located 18 kilometres (11 mi) to the east of Rotorua, and beneath the peaks of the Tarawera massif i.e. Wahanga, Ruawahia, Tarawera and Koa. Tarawera means "Burnt Spear", named by a visiting hunter who left his bird spears in a hut and on returning the following season found that both his spears and hut had been turned to ashes.
Lake Rotorua is the second largest lake in the North Island of New Zealand by surface area, and covers 79.8 km2. With a mean depth of only 10 metres it is considerably smaller than nearby Lake Tarawera in terms of volume of water. It is located within the Rotorua Caldera in the Bay of Plenty Region.
The Waimangu Geyser, located near Rotorua in New Zealand, was for a time the most powerful geyser in the world.
Orakei Korako is a highly active geothermal area most notable for its series of fault-stepped sinter terraces, located in a valley north of Taupō on the banks of the Waikato River in the Taupō Volcanic Zone, New Zealand. It is also known as "The Hidden Valley".
Frying Pan Lake is the world's largest hot spring. It is located in the Echo Crater of the Waimangu Volcanic Rift Valley, New Zealand and its acidic water maintains a temperature of about 50 to 60 °C (122–140 °F). The Lake covers 38,000 square metres in part of the volcanic crater and the shallow lake is only 5.5 metres (18 ft) deep, but at vents, it can go down to 18.3 metres (60 ft).
The region around the city of Rotorua, in New Zealand's North Island, contains several lakes which have a total area of about 250 square kilometres. The term Rotorua lakes is ambiguous as it has been used historically for a New Zealand administrative area. From biggest to smallest, these are Lake Rotorua, Lake Tarawera, Lake Rotoiti, Lake Rotomā, Lake Okataina, Lake Rotoehu, Lake Rotomahana, Lake Rerewhakaaitu, Lake Rotokākahi, Lake Okareka and Lake Tikitapu. There are also smaller lakes including: Lake Okaro, Lake Rotokawa, Lake Rotokawau and Lake Rotongata. Most of the lakes have formed due to volcanic activity and some have current geothermal activity. The region is part of the Taupō Volcanic Zone, the world's most active area of explosive silicic volcanic activity in geologically recent time.
Alfred Patchett Warbrick was a New Zealand boatbuilder, rugby player and tourist guide.
Inferno Crater Lake is a large hot spring located in the Waimangu Volcanic Rift Valley on the North Island of New Zealand, and the largest geyser-like feature in the world. The actual geyser is not visible, as it plays underwater at the bottom of the lake, however, fumaroles are visible on the lake's shore and the rock wall behind it.
The 1886 eruption of Mount Tarawera was a violent volcanic eruption that occurred in the early hours of 10 June 1886 at Mount Tarawera, near Rotorua on New Zealand's North Island. The eruption reached an estimated volcanic explosivity index (VEI) of 5 and killed an estimated 120 people, making it the largest and deadliest in New Zealand during the past 500 years, a period that includes the entirety of European history in New Zealand.
Ōkataina Caldera is a volcanic caldera and its associated volcanoes located in Taupō Volcanic Zone of New Zealand's North Island. It has several actual or postulated sub calderas. The Ōkataina Caldera is just east of the smaller separate Rotorua Caldera and southwest of the much smaller Rotomā Embayment which is usually regarded as an associated volcano. It shows high rates of explosive rhyolitic volcanism although its last eruption was basaltic. The postulated Haroharo Caldera contained within it has sometimes been described in almost interchangeable terms with the Ōkataina Caldera or volcanic complex or centre and by other authors as a separate complex defined by gravitational and magnetic features.. Since 2010 other terms such as the Haroharo vent alignment, Utu Caldera, Matahina Caldera, Rotoiti Caldera and a postulated Kawerau Caldera are often used, rather than a Haroharo Caldera classification.
Maunga Kākaramea is a 743 metres (2,438 ft) high dacite volcano located between Rotorua and Taupō in the North Island Volcanic Plateau. It has multiple steaming features and a picturesque crater lake reached by a short walk from the nearest road and has a nearby geothermal area.
Maungaongaonga is an 825 metres (2,707 ft) high dacite volcano located between Rotorua and Taupō in the North Island Volcanic Plateau. The area of the mountain is a scenic reserve and some of its southern slopes are highly geothermally active.
The Ngapouri-Rotomahana Fault is a seismically and volcanically active area of the central North Island of New Zealand.
Lake Rotomakariri was a lake which formerly existed in the basin that is now occupied by Lake Rotomahana, in the Bay of Plenty region of New Zealand's North Island. The lake's name was in contrast to the nearby Lake Rotomahana, which prior to the 1886 eruption of Mount Tarawera, was a shallower warm water lake. Prior to this eruption, Lake Rotomakariri sat in a shallow basin surrounded by marshes, draining into Lake Tarawera by Awapurohe Creek and Rotomahana's outflow of Kaiwaka Stream. The eruption of Mount Tarawera initially destroyed Lake Rotomakariri and its lakeside village with the loss of 19 lives, though water entering the new crater gradually refilled Lake Rotomakariri after volcanic activity subsided. As water accumulated over the decade after the eruption, Lake Rotomakariri was absorbed by the larger Lake Rotomahana, which eventually rose to about 36–48 m (118–157 ft) above its pre-eruption level due to the previous outflow of the basin being blocked by ashfall.
↑ Bunn, Rex; Nolden, Sascha (7 June 2017). "Forensic cartography with Hochstetter's 1859 Pink and White Terraces survey: Te Otukapuarangi and Te Tarata". Journal of the Royal Society of New Zealand. 48: 39–56. doi:10.1080/03036758.2017.1329748. ISSN0303-6758. S2CID134907436.
↑ Brock, Thomas D.; Brock, M. Louise (December 1970). "The Algae of Waimangu Cauldron: Distribution in relation to pH". Journal of Phycology. 6 (4): 371–375. doi:10.1111/j.1529-8817.1970.tb02410.x. S2CID85921216.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
