Extinct or Dead Volcanoes. The vent of an extinct volcano is blocked and its crater is filled with rain water to form a crater lake. Vegetation starts growing on it. The possibility of future explosion becomes remote. Many time an extinct volcano suddenly becomes active. This has happened in case of Krakatoa volcano. The Island of Krakatoa is situated in the Sunda Strait between the Island of Java and Sumatra. Its eruption in the year 1883 blew off the top of the mountain by an explosion which caused tidal waves about 16 meters high, killing 36000 people in west java. The sound of explosion was heard as far as Istambul (Turkey) in the west and Tokyo in the east. The volcanic dust and gases encircling the globe in the atmosphere caused strange sunrise and sunset conditions for about three years. Today Krakatoa is only a low Island with a lake inside its crater.