text: Krakatoa (krākətō′ ə, krä–) or Krakatau (kräkätou′ ), volcanic island, c.5 sq mi (13 sq km), W Indonesia, in Sunda Strait between Java and Sumatra; rising to 2,667 ft (813 m). A momentous volcanic explosion on Aug. 23, 1883, blew up most of the island and altered the configuration of the strait; the accompanying tsunami caused great destruction and loss of life along the nearby coasts of Java and Sumatra. The explosion is classed as one of the largest volcanic eruptions in modern times; so great was the outpouring of ashes and lava that new islands were formed, and debris was scattered across the Indian Ocean as far as Madagascar. Since then there have been several lesser eruptions.