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Tanna
  |  Ambae  |  Karua  |  Ambrym  |  Lopevi  |  Gaua  |  Epi

Yasur, the most accessible active volcano in the world

Coral dating and GPS measurements  |  Devastating acid rains  |  Formidable volcanic bombs  |  Monitoring Yasur's activity  |  Seismic activity, torrential rains, landslides  |  Volcanic hazard for the population

Tanna Island belongs to the central portion of the New Hebrides Arc, a 3 to 6 million year-old complex extending from the Banks Islands in the north to Hunter Island in the south. There, the subduction rate averages 118 mm per year. Volcanic activity began about 3 million years ago with the formation of the "Green Hill" series. Today, this activity is limited to the Yenkahe volcanic complex, with the Yasur  occupying the western portion (latitude 19.52°S, longitude 169.43E).

Yasur's current activity, documented now for at least 200 years, is of the Strombolian and Vulcanian type. Over the last ten thousand years or so, lava and pyroclastic flows have occurred, building up the old volcanic cone of Ombus. The summit of Yasur reaches 365 m altitude, and its activity varies in intensity. Five alert levels have been defined (0 to 4).

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