McDonald Islands (volcano) McDonald Islands (volcano) The McDonald Islands () are the peaks of a volcano in the southern Indian Ocean in the vicinity of Heard Island (). The islands are Australian external territory. Prior to 1992, the volcano had not erupted in the previous 75,000 years. The McDonald Islands volcano comprises three islands: McDonald Island, Flat Island (which later merged with McDonald Island) and Meyer Rock. The islands are mostly composed of phonolitic low-silica pumice, dikes and lava domes, and sit atop a submarine plateau, the Kerguelen plateau. They are located about 75 km from Heard Island. McDonald Island is the largest
Volcano upper atmosphere (or stratosphere). Historically, volcanic winters have caused catastrophic famines. The word "volcano" is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is called volcanology, sometimes spelled "vulcanology". At the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock. Because the crust is very thin at these ridges due to the pull of the tectonic plates, the release of