An eruption of Anak Krakatau began in mid-July from the 1978 crater (see figures 1 and 2), ejecting tephra and extruding lava that flowed into the sea at the island's W coast. Lava extrusion had ended by early September, but tephra emission continued at varying levels of intensity through the end of the month.

Figure 2. Oblique airphoto of Anak Krakatau, 12 September 1979, looking approximately NW. Verlaten Island (caldera rim) is in the background. An eruption column rises from the 1978 crater. Photo taken by Maurice Krafft.

Geological Summary. The renowned Krakatau (frequently mis-named as Krakatoa) volcano lies in the Sunda Strait between Java and Sumatra. Collapse of an older edifice, perhaps in 416 or 535 CE, formed a 7-km-wide caldera. Remnants of that volcano are preserved in Verlaten and Lang Islands; subsequently the Rakata, Danan, and Perbuwatan cones were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan, and left only a remnant of Rakata. This eruption caused more than 36,000 fatalities, most as a result of tsunamis that swept the adjacent coastlines of Sumatra and Java. Pyroclastic surges traveled 40 km across the Sunda Strait and reached the Sumatra coast. After a quiescence of less than a half century, the post-collapse cone of Anak Krakatau (Child of Krakatau) was constructed within the 1883 caldera at a point between the former Danan and Perbuwatan cones. Anak Krakatau has been the site of frequent eruptions since 1927.

Information Contacts: Maurice Krafft, Cernay, France.