Mount Yasur
Encyclopedia
Mount Yasur is an active volcano on Tanna Island, Vanuatu
(lat/long 19.52 S, 169.43 E) with a height of 361 m (1,184 ft) above sea level, located on the coast near Sulphur Bay
. It lies to the southeast of the taller Mount Tukosmera
, which was active in the Pleistocene
. It has a largely unvegetated pyroclastic cone with a nearly-circular summit crater 400 m in diameter. It is a stratovolcano
, caused by the eastward-moving Indo-Australian Plate
being subducted under the westward-moving Pacific Plate
. It has been erupting nearly continuously for centuries, although it can usually be approached safely. Its eruptions, which often occur several times an hour, are classified as Strombolian
or Vulcanian
.
The glow of the volcano was apparently what attracted Captain James Cook
on the first European journey to the island in 1774. Today the mountain is a sacred area for the John Frum
cargo cult
. Members of the cult revere John Frum, a deified messenger who foretold the bringing of wealth to the island by American forces, and believe he resides in Mount Yasur with his countrymen. The village of Sulphur Bay, the center of the movement, claims the volcano as part of their territory.
Because of the importance of the volcano to the tourism industry in Tanna, the local government has created levels to restrict people's access:
Level 0 - Low activity, access to the crater allowed; Level 1 - Normal activity, access to the crater allowed; Level 2 - Moderate to high activity, lava bombs may land beyond the crater rim, access to the crater is closed; Level 3 - Severe activity with loud explosions, lava bombs ejected up to hundreds of metres outside the crater and large plumes of smoke and ash, access to the summit zone is closed; Level 4 - Major eruption affecting large areas around the volcano and possibly other parts of Tanna and even neighbouring islands, all access closed.
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...
(lat/long 19.52 S, 169.43 E) with a height of 361 m (1,184 ft) above sea level, located on the coast near Sulphur Bay
Sulphur Bay
Sulphur Bay is a bay on the eastern side of Tanna island in Vanuatu. Nearby is Mount Yasur, called the world's most accessible volcano, and the area is the center of the John Frum cargo cult, a movement that believes their savior, an American World War II GI, resides within Yasur...
. It lies to the southeast of the taller Mount Tukosmera
Mount Tukosmera
Mount Tukosmera is the tallest mountain on Tanna, Vanuatu. It is located in the northwest of the island. It was a volcano in the Pleistocene, but is no longer active, as is Mount Yasur....
, which was active in the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
. It has a largely unvegetated pyroclastic cone with a nearly-circular summit crater 400 m in diameter. It is a stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...
, caused by the eastward-moving Indo-Australian Plate
Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and surrounding ocean, and extends northwest to include the Indian subcontinent and adjacent waters...
being subducted under the westward-moving Pacific Plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
. It has been erupting nearly continuously for centuries, although it can usually be approached safely. Its eruptions, which often occur several times an hour, are classified as Strombolian
Strombolian eruption
Strombolian eruptions are relatively low-level volcanic eruptions, named after the Italian volcano Stromboli, where such eruptions consist of ejection of incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters...
or Vulcanian
Vulcanian eruption
The term Vulcanian was first used by Giuseppe Mercalli, witnessing the 1888-1890 eruptions on the island of Vulcano. His description of the eruption style is now used all over the world for eruptions characterised by a dense cloud of ash-laden gas exploding from the crater and rising high above the...
.
The glow of the volcano was apparently what attracted Captain James Cook
James Cook
Captain James Cook, FRS, RN was a British explorer, navigator and cartographer who ultimately rose to the rank of captain in the Royal Navy...
on the first European journey to the island in 1774. Today the mountain is a sacred area for the John Frum
John Frum
John Frum is a figure associated with cargo cults on the island of Tanna in Vanuatu. He is often depicted as an American World War II serviceman, who will bring wealth and prosperity to the people if they follow him. He is sometimes portrayed as black, sometimes as white; from David Attenborough's...
cargo cult
Cargo cult
A cargo cult is a religious practice that has appeared in many traditional pre-industrial tribal societies in the wake of interaction with technologically advanced cultures. The cults focus on obtaining the material wealth of the advanced culture through magic and religious rituals and practices...
. Members of the cult revere John Frum, a deified messenger who foretold the bringing of wealth to the island by American forces, and believe he resides in Mount Yasur with his countrymen. The village of Sulphur Bay, the center of the movement, claims the volcano as part of their territory.
Because of the importance of the volcano to the tourism industry in Tanna, the local government has created levels to restrict people's access:
Level 0 - Low activity, access to the crater allowed; Level 1 - Normal activity, access to the crater allowed; Level 2 - Moderate to high activity, lava bombs may land beyond the crater rim, access to the crater is closed; Level 3 - Severe activity with loud explosions, lava bombs ejected up to hundreds of metres outside the crater and large plumes of smoke and ash, access to the summit zone is closed; Level 4 - Major eruption affecting large areas around the volcano and possibly other parts of Tanna and even neighbouring islands, all access closed.