Volcano Pompeii. Before its catastrophic eruption of 1991, Pinatubo was an inconspicuous volcano, unknown to most people in the surrounding areas. Two other examples are the long-dormant Soufrière Hills volcano on the island of Montserrat, thought to be extinct before activity resumed in 1995, and Fourpeaked Mountain in Alaska, which, before its September 2006 eruption, had not erupted since before 8000 BCE and had long been thought to be extinct. The three common popular classifications of volcanoes can be subjective and some volcanoes thought to have been extinct have erupted again. To help prevent people from falsely believing they are not
Barren Island (Andaman Islands) National Institute of Oceanography (NIO) spotted the volcano erupting on 23 January 2017. Abhay Mudholkar, the head of the team, said, "The volcano is erupting in small episodes of about five to ten minutes. During the day, only ash clouds were observed. However, after sundown, red lava fountains were spewing from the crater into the atmosphere and hot lava flowed streaming down its slopes." Based on Ar-Ar dating of samples from Barren Island it is now established that the oldest subaerial lava flows of the volcano are 1.6 million years old and the volcano is located on an oceanic crust