22 December 2018 Eruptions and Tsunami

Rakata Island. The tsunami trim line is shown in dashed red and the
location of the high runup point of ~ 85 m is indicated. (Borrero et al.)

The eruptions during the day on 22 December were not noticeably different than throughout the cycle that started in June 2018. In fact the first signal that a major event was taking place was the tsunami arriving on the nearest shores of Java and Sumatra in the early evening, about 30 minutes after the time of the estimated flank failure. Because the collapse was on the side opposite the islands’ populated coasts, and there was no unusual ground shaking, it was not initially known what had even caused the tsunami. Retrospectively, eyewitnesses noted that the glowing lava flow became obscured in darkness shortly before the tsunami’s arrival, likely because of ash flow and steam hitting the ocean on the opposite side. Photographer Øystein Lund Andersen’s photographed the obscured island 11 minutes before the tsunami arrived at Anyer-Carita beach on Java, about 30 miles SE of the volcano.

Contents

• History
• Post-tsunami Eruptions and Cone Regrowth
• 22 December 2018 Eruptions and Tsunami
• Tsunami Impact on Nearby Unpopulated Islands
• Tsunami Impact on Populated Coastlines of Sumatra and Java
• Tsunamagenic Flank Failure Scenarios
• Seismic Signals, Early Warning Wystems and Event Documentation
• Lessons Learned
• Event Information
• Krakatau Islands History
• Media Reports, Photos and Video
• Research Articles