Kuwae

From Wikipedia, the free encyclopedia

Kueae also called Karua is a submarine volcano between Epi and Tongoa islands, one of the most active volcanoes of Vanuatu.

1 Cataclysmic event
2 Climatic consequences of the event
3 Recent activity
4 See also
5 Notes

[edit] Cataclysmic event

Tongoa and Epi islands once formed part of a larger island called Kuwae. Local folklore tells of a cataclysmic eruption that destroyed this island, leaving the two smaller islands and an oval-shaped 12 x 6 km caldera in between. Collapse associated with caldera formation may have been as much as 1,100 m. 32–39 cubic km of magma was erupted, making the Kuwae eruption one of the largest in the last 10,000 years.^[1]

In Antarctica and Greenland ice cores the eruption is revealed as a spike in sulfate concentration showing that the release in form of particles was higher than any other eruption since.^[2] Also the ice core analyses are able to pinpoint the event to late 1452 or early 1453.^[3] This volume of expelled matter is more than six times larger than that of the 1991 Pinatubo eruption and would have caused severe cooling of the entire planet the following three years.

[edit] Climatic consequences of the event

A study by Dr Kevin Pang of the Jet Propulsion Laboratory^[4] drew on evidence found in tree rings, ice cores and in the historic records of civilizations in Europe and China. Oak panels of British portrait paintings had abnormally narrow rings in 1453–55.

In Sweden, corn tithes fell to zero as the crops failed; western U.S. bristlecone pines show frost damage in 1453; and the growth of European and Chinese trees was stunted in 1453–57.

According to the history of the Ming Dynasty in China in the spring of 1453, "Nonstop snow damaged wheat crops." Later that year, as the dust obscured the sunlight, "Several feet of snow fell in six provinces; tens of thousands of people froze to death."

Early in 1454, "it snowed for 40 days south of the Yangtze River and countless died of cold and famine." Lakes and rivers were frozen, and the Yellow Sea was icebound out to 20 km from shore.

The eruption occurred just before the Fall of Constantinople, the last bastion of the once-mighty Byzantine Empire. The Ottoman Turks, led by Sultan Mehmed II, laid siege to the city on April 5, 1453, and conquered it on May 29. Pang found mention of the volcano's aftereffects in chronicles of the city's last days. Historians noted the city's gardens that spring produced very little. On May 25, a thunderstorm burst on the city: "It was impossible to stand up against the hail, and the rain came down in such torrents that whole streets were flooded". On the night of May 22, 1453, the moon, symbol of Constantinople, rose in dark eclipse, fulfilling a prophecy of the city's demise. Four days later, the whole city was blotted out by a thick fog, a condition unknown in that part of the world in May. When the fog lifted that evening, "flames engulfed the dome of the Hagia Sophia, and lights, too, could be seen from the walls, glimmering in the distant countryside far behind the Turkish camp (to the west)," historians noted. Residents of the city thought the strange light was due to reflection from a fire set by the Turkish attackers. Pang said, however, such a "fire" was an optical illusion due to the reflection of intensely red twilight glow by clouds of volcanic ash high in the atmosphere. Many such false fire alarms were reported worldwide after the 1883 Krakatoa eruption in Indonesia.

"I conclude that Kuwae erupted in early 1453," Pang said. "The residual volcanic cloud could have made the apocalyptic June 1456 apparition of the Comet Halley look 'red' with a 'golden' tail, as reported by contemporary astronomers."

[edit] Recent activity

Islands have regularly formed in Kuwae caldera. The 1897–1901 eruption built an island 1 km long and 15 m high. It disappeared within 6 months. The 1948–1949 eruption formed an island and built a cone 1.6 km in diameter and 100 m high. This island also lasted less than one year. All the islands have disappeared due to wave action and caldera floor movements. In 1959 the island reappeared for a short time, and again in 1971. The last structure remained an island until 1975.^[5]

Activity at present at Kuwae is confined to intermittent fumaroles activity which stain the water yellow. Over the top of the volcano hydrogen sulfide bubbles reach the surface.^[6]