Жаңа Зеландиядағы Уакаари жанартауы

Island volcano in New Zealand's Bay of Plenty

Whakaari / White Island (, , lit. "the dramatic volcano"), also known as White Island or Whakaari, is an active andesite stratovolcano situated from the east coast of the North Island of New Zealand, in the Bay of Plenty. The island covers an area of approximately , which is just the peak of a much larger submarine volcano. The island is New Zealand's most active cone volcano, and has been built up by continuous volcanic activity over the past 150,000 years. The nearest mainland towns are Whakatāne and Tauranga. The island has been in a nearly continuous stage of releasing volcanic gas at least since it was sighted by James Cook in 1769. Whakaari erupted continually from December 1975 until September 2000, and also erupted in 2012, 2016, and 2019. Sulphur was mined on the island until the 1930s. Ten miners were killed in 1914 when part of the crater wall collapsed. A large eruption occurred at 14:11 on 9 December 2019, which resulted in 22 fatalities, including two people who were missing and ruled to be dead by a coroner. Twenty five survivors were injured, many critically and with severe burns. Forty seven people were reportedly on the island when it erupted. A second eruption closely followed the first.

Whakaari / White Island is an irregular oval in shape, with a length (northwest–southeast) of and a width of , and covers an area of approximately The exposed island is only the peak of a much larger submarine volcano, which rises up to above the nearby seafloor. The island is generally rugged, with cliffs surrounding most of the coast. The only exceptions are to the southeast of the crater, where ash and boulder slopes descend to Te Awapuia Bay (also known as Crater Bay), the site of derelict buildings and the island's wharf. This bay lies between a prominent headland, Troup Head, at the island's southeastern extreme, and the island's southernmost point, Otaketake, which is the site of one of the island's gannet colonies. Another colony exists at Te Hokowhitu, the cliff which forms much of the western coast of the island. The modern crater floor of Whakaari / White Island lies less than above sea level and is largely covered by material from the 1914 debris avalanche. The main crater contains three coalescing sub craters. The sub craters are aligned NW SE within the amphitheatre shaped Central Cone. The open sea breaches the south eastern crater wall in three places to form Shark, Te Awapuia, and Wilson bays, which Troup Head and Pinnacle Head separate from each other. Long lived, semi continuous, weak, hydrothermal explosions, similar to those occurring in the Western sub crater today, are regarded to have formed these three bays as hydrothermal explosion craters. The amphitheatre shaped crater of the modern Central Cone is argued to have been created by the collapse of the former cone of the White Island Volcano to the southwest. Based on extrapolating 20 m GIS contour data to enclose the present crater and upwards with a maximum slope angle of 30°, the former pre collapse summit was inferred to have been high. Side scan and bathymetric data indicate possible debris flows associated with its collapse that can be traced back to the current crater on White Island. One of these debris flows exited the crater on the southern side of Troup Head and towards the southeast. It produced well defined boulder covered lobes on the seafloor. Another debris flow exited the modern crater on the northern side of Troup Head and through several submarine valleys towards the east into deep water. It produced boulder covered valley fill deposits. The latter debris flow was large enough to have produced a significant tsunami. As a result of the collapse of the former cone of the White Island Volcano, it is suspected to have generated a high tsunami that flooded the coast of Bay of Plenty as much as inland between 3,000 and 2,200 B. P.

Whakaari / White Island lies in the northern end of the Taupō Volcanic Zone. The Taupō Volcanic Zone forms the southernmost segment of the long Tonga–Kermadec–Taupō volcanic arc system and the Lau Basin–Havre Trough–Ngatoro Basin back arc basin system. Although Strombolian activity occurred from the late seventies to the mid eighties, explosive eruptions at Whakaari / White Island are typically phreatic or phreatomagmatic in style. The lava flows, ash, and pyroclastic flows produced by historic and prehistoric eruptions are andesitic and dacitic in composition. These eruptions also produce discrete craters within crater fill deposits of the Central Cone. Since 1826, there has been a minimum of 28 phreatic or phreatomagmatic eruptions. In addition, prehistoric eruptions have also extruded lava. The lava flows from these prehistoric eruptions are exposed crater walls of the Central Cone. For example, this volcano provides a readily studied example of the type of volcanic magmatic–hydrothermal system involved in the generation of porphyry copper deposits. Volcanologists from the GeoNet Project continually monitor the volcano's activity via surveillance cameras. Survey pegs, magnetometers and seismography equipment for early earthquake warnings via radio were installed on the crater walls in 1976. At most times the volcanic activity is limited to steaming fumaroles and boiling mud, and the island is typically on an alert level rating of 1 or 2 on a scale of 0 to 5; as "Level 2 is the highest alert level before an eruption takes place and indicates 'moderate to heightened volcanic unrest' with the 'potential for eruption hazards.'" The volcano is also monitored by the Deep Earth Carbon Degassing Project. In March 2000, three small vents appeared in the main crater and began belching ash which covered the island in fine grey powder. An eruption on 27 July 2000 blanketed the island with mud and scoria and a new crater appeared. Major eruptions in 1981–83 altered much of the island's landscape and destroyed the extensive pōhutukawa forest. The large crater created at that time now contains a lake, whose level varies substantially. Between July and August 2012 the island showed signs of increased activity with lake and gas levels rising from inside the crater. On 5 August 2012 a minor eruption occurred, sending ash into the air. More eruptions have followed since. Ongoing volcanic activity and tremors on 25 January 2013 suggested another eruption was imminent. A small eruption occurred on 20 August 2013 at 10:23 am, lasting for ten minutes and producing mostly steam.

In November 2019, background activity at Whakaari increased and gas, steam and mud was being ejected from the crater. At 14:11 NZDT on 9 December 2019, Whakaari / White Island erupted. It was reported that there were forty seven people on the island when the eruption happened. Twenty two people were killed, including two people who are missing and confirmed dead on 23 January 2020, The ongoing seismic and volcanic activity in the area and subsequently heavy rainfall as well as low visibility and toxic gases all hampered recovery efforts. Experts identified the event as a phreatic eruption: a release of steam and volcanic gases which caused an explosion, launching rock and ash into the air. Minor ash emissions were observed on 23 and 26 December, but no further eruptions occurred. Visual observations conducted in January showed that lava had been extruded into the vents created by the eruption on 9 December.

The Māori name Whakaari is recorded in multiple 19th century texts by Europeans, with one mention dating back to 1849, though spelling varied including Wakaari, Whakari, and Whaka ari. The name Whakaari means "to make visible" or "exposed to view". The full Māori name for the island is te puia whakaari, meaning "The Dramatic Volcano". According to LINZ this name came from the dense clouds of white steam emanating from it. This makes it one of many places in New Zealand with dual Māori and English names.

Some Māori myths describe Whakaari as part of Ngātoro i rangi's ascent of Tongariro. In one account, he called on his ancestors for warmth; the fire was kindled on Whakaari and brought to him. Other versions of this story are similar but it is his sisters, or the gods, who send him warmth from Whakaari. Mining came to a halt in September 1914, when part of the western crater rim collapsed, creating a lahar that killed all 10 workers, who disappeared without a trace. Only a camp cat survived, found some days afterwards by the resupply ship and dubbed "Peter the Great". In 1923, mining was again attempted but, learning from the 1914 disaster, the miners built their huts on a flat part of the island near a gannet colony. Each day they would lower their boat into the sea from a gantry, and row around to the mining factory wharf in Crater Bay. If the sea was rough they had to clamber around the rocks on a very narrow track on the crater's edge. Before the days of antibiotics, sulphur was used as an antibacterial agent in medicines, in the making of match heads, and for sterilising wine corks. The sulphur was hauled to the crushing plant in small rail trucks, and a bagging facility was also constructed. However, there was not enough sulphur in the material mined at the island, so the ground up rock was used as a component of agricultural fertiliser. Mining ended in the 1930s, because of the inadequate mineral content in the fertiliser. The remains of the buildings involved can still be seen, heavily corroded by the sulphuric gases.

The ownership of Whakaari / White Island was one of the first two cases heard by the Native Land Court of New Zealand (now called the Māori Land Court), the other being ownership of nearby Motuhora. Retireti Tapihana (Tapsell) brought the case in 1867, claiming ownership. Retireti was the son of Phillip Tapsell and Hine i tūrama Ngātiki. Ownership was awarded jointly to Retireti Tapihana and his sister Katherine Simpkins. The island is now privately owned by the Buttle family trust, having been bought by George Raymond Buttle, a stockbroker, in 1936. Buttle later refused to sell it to the government, but agreed in 1952 that it be declared a private scenic reserve. In 2012, the island's title was transferred to the Whakaari Trust, whose shareholders are Peter, Andrew and James Buttle.

The island is not included in the boundaries of a territorial authority council (district council) and the Minister of Local Government is its territorial authority, with support from the Department of Internal Affairs. The functions of the territorial authority are limited, as the island is uninhabited, the land is undeveloped and it is privately owned.

Whakaari / White Island is one of New Zealand's main breeding colonies for Australasian gannets. Thousands of gannets come to the island each year to mate, raise chicks, and feed on the fish in the water around it. There is little vegetation on the island itself, but seaweed grows in the waters around it and gannet parents harvest it to cool off chicks. An ornithologist who visited in 1912 found five species and identified four; in addition to gannets they found red billed gulls, great winged petrels, and white fronted terns. BirdLife International has declared the island to be an Important Bird Area because of the gannets' nesting colony.

Whakaari / White Island is privately owned. It was declared a private scenic reserve in 1953, and is subject to the provisions of the Reserves Act 1977. Visitors cannot land without permission. However, it is easily accessible by authorised tourist operators.