Krakatoa is a volcano in Indonesia that lies at the convergent boundary between the Eurasian and Indo-Australian tectonic plates. It was formed sometime within the past million years, when the two plates collided and the Indo-Australian plate began sliding under the Eurasian plate. The volcano is famous for its major eruption in 1883, which killed 36,000 people and was one of the deadliest eruptions in human history.Continue Reading
This eruption created tsunamis that swept along the coasts of the nearby islands of Sumatra and Java, and the explosion was so loud that it was heard more than 2,000 miles away in Australia.
Prior to the eruption in 1883, the massive Krakatoa volcano was spread out over three islands: Krakatoa, Verlaten and Lang. Perlaten and Lang Islands had been formed by two other volcanoes, Danan and Perbuwatan. However, this eruption was so violent that it destroyed most of all three volcanic cones and much of Krakatoa Island.
In 1927, a new island began to surface in between the three islands, caused by further small eruptions of Krakatoa. The name of this new island is Anak Krakatoa, which means Son of Krakatoa, and this new caldera has experienced quite frequent but fairly minor eruptions since it emerged from the ocean.Learn more about Plate Tectonics
The most active plate boundary is in the Pacific Ocean basin. Several tectonic plates collide in this area, which is known as the Ring of Fire due to the high number of volcanoes, earthquakes, deep sea trenches and other seismic activities occurring on its rim.Full Answer >
When two tectonic plates pull apart from one another, they form a divergent plate boundary. In addition to divergent boundaries, there are two other common types of boundaries: convergent boundaries and transform boundaries, also known as strike-slip boundaries.Full Answer >
The San Andreas Fault exemplifies a transform fault plate boundary. Transform fault boundaries consist of two plates sliding against each other in a horizontal motion.Full Answer >
Kilauea was not formed by tectonic activity at a plate boundary. Instead, it is the result of a geologic hot spot beneath the middle of the Pacific plate. This hot spot also built the other islands of the Hawaiian chain, beginning with Kauai about 5 million years ago.Full Answer >