PVMBG reported that there were four explosive events at Anak Krakatau on 14 March, recorded at 0816, 1711, 1716, and 2126, producing white plumes that drifted S and SW. An event at 0953 on 16 March produced a white plume that rose 1 km and drifted N. White plumes from events at 0605 and 0905 on 18 March generated white plumes that rose 500 m and drifted N. The Alert Level remained at 3 (on a scale of 1-4), and residents were warned to remain outside of the 5-km radius hazard zone from the crater.

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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)