Dormant and reactivated Volcano

narcondam island, india, classified dormant volcano geological survey of india

it difficult distinguish extinct volcano dormant (inactive) one. volcanoes considered extinct if there no written records of activity. nevertheless, volcanoes may remain dormant long period of time. example, yellowstone has repose/recharge period of around 700,000 years, , toba of around 380,000 years. vesuvius described roman writers having been covered gardens , vineyards before eruption of 79 ce, destroyed towns of herculaneum , pompeii. before catastrophic eruption of 1991, pinatubo inconspicuous volcano, unknown people in surrounding areas. 2 other examples long-dormant soufrière hills volcano on island of montserrat, thought extinct before activity resumed in 1995, , fourpeaked mountain in alaska, which, before september 2006 eruption, had not erupted since before 8000 bce , had long been thought extinct. climate change can reportedly trigger volcanic activity in sensitive areas changing pressure of ice or seawater , extreme weather.