The volcanoes in Indonesia are among the most active of the Pacific Ring of Fire . They are formed due to subduction zones of three main active tectonic plates namely the Eurasian Plate , Pacific Plate , and Indo-Australian Plate . Some of the volcanoes are notable for their eruptions , for instance , Krakatau for its global effects in 1883 , Lake Toba for its supervolcanic eruption estimated to have occurred 74,000 BP , which was responsible for six years of volcanic winter , and Mount Tambora , for the most violent eruption in recorded history in 1815 . The eruption of Mount Tambora caused widespread harvest failures in Northern Europe , the Northeastern United States , and eastern Canada in 1816 , which was known as the Year Without a Summer
Year Without a Summer
Year Without a Summer
Ring of Fire