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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 former site of the Pink and White Terraces, as well as the location of the Waimangu Geyser, which was active from 1900 to 1904. The area has been increasingly accessible as a tourist attraction and contains Frying Pan Lake, which is the largest hot spring in the world,〔(【引用サイトリンク】title=The Eruption & Birth of Waimangu )〕 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.〔(【引用サイトリンク】title=World & National Importance )〕 ''Waimangu'' means 'black water' in Māori, the indigenous language of New Zealand. 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 kereru, tui, fantail, bellbird, and pukeko, as well as introduced bird species such as mynah, magpie, shining cuckoo, 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.〔Waimangu Wanderer Guide, October 2013〕 Many of Waimangu's geothermal features are ranked as Category A - extremely important, of international significance.〔(【引用サイトリンク】title=Classifying geothermal systems )〕 ==History== The largest volcanic eruption in the past 700 years in New Zealand, the 1886 Mount Tarawera eruption,〔(【引用サイトリンク】title=Historic volcanic Activity )〕 created the geo-thermal area of the Waimangu Volcanic Rift Valley. The valley lies at the south-western end of the 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 thick.〔(【引用サイトリンク】title=Waimangu: Geology )〕 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.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Waimangu Volcanic Rift Valley」の詳細全文を読む スポンサード リンク
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