Kuwae

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Kuwae is a submarine volcano between Épi and Tongoa, one of the most active volcanoes in Vanuatu. He broke out around the year 1453 and reached the magnitude 6 on the Vulkanexplosivitätsindex.

The eruption

Tongoa and Épi were once parts of a larger island called Kuwae. The local tradition tells of an eruption that destroyed the island and the two islands as well as present an oval, 12 km × 6 km wide caldera left behind. The Kuwae eruption was one of the largest in the last 10,000 years; there were ejected 32-39 km3 of magma.

In the Antarctic and Greenland can demonstrate, by the eruption of ice cores. The measured there sulfate concentration indicates that the emission of particles was greater than any eruption since then. The Eisbohrkernanalyse allows to date the event in 1452 or 1453. The volume of the ejected matter was about three times as large as the eruption of Mount Pinatubo in 1991.

Consequences for the climate

The eruption has led to a cooling of the climate on Earth in the following years (see Volcanic winter). A study by Kevin Pang 's Jet Propulsion Laboratory found evidence in tree rings, ice cores and historical records from Europe and China. Oak panels by British portrait images indicate extremely narrow rings for the years 1453-1455. In Sweden, the harvest failed to materialize and the grain tithe fell to zero; Pines of the North American West show frost damage in the year in 1453. The growth of European and Chinese trees was slowed from 1453 to 1457.

. According to the history of the Ming Dynasty in China destroyed incessant snowfall the wheat in the spring of 1453, the same year as the dust obscured the sun, " fell several yards of snow in six provinces; tens of thousands of people froze to death ". For the year 1454 is reported: " it snowed for 40 days south of the Yangtze River, and countless died of cold and hunger ", and the Yellow Sea was frozen up to 20 km off the coast.

The eruption occurred shortly before the conquest of Constantinople Opel, the last bastion of the Byzantine Empire. The Ottoman Turks under Sultan Mehmed II besieged the city since April 5, 1453 and conquered it on 29 May. Pang found evidence of the effects of the volcanic eruption in chronicles of the city. The gardens of the city have yielded little return this spring. On May 25, a storm raged over the city: " it has not been possible to resist the hail, and the rain poured down in such streams that whole streets were flooded ." On the night of May 22, darkened, the moon, the symbol of Constantinople Opel.

Four days later, the entire city was enveloped in a dense fog. When the smoke cleared in the evening, " Haghia Sophia appeared immersed in flames, and from the ramparts of lights could be seen flickering in the distance behind the Turkish camp." The inhabitants of the city felt the strange light would be a reflection of a set of the attackers fire. However, it was an optical illusion, a reflection of the extremely red twilight of clouds of volcanic ash high up in the atmosphere. Many such, false fire alarms ' were also reported worldwide after the eruption of Krakatoa in 1883.

The special appearance of Halley's comet in June 1456 as " red with a golden tail ", as reported by contemporary astronomers, was obviously a result of the eruption.

Today's activity

In the Kuwae - caldera islands have formed regularly. The eruption from 1897 to 1901 formed an island that was 1000 m long and 15 m high. She disappeared after six months. The eruption from 1948 to 1949 also formed an island which disappeared again. This disappearance has its causes in the waves and in the basic flow of the caldera. In the years 1959 and 1971 the island for a short time reappeared.

The current activity in Kuwae limited to fumaroles that color the water yellow. About the volcanic peaks reach bubbles of hydrogen sulfide the surface.