STEER - SUNDA STRAIT TSUNAMI (INDONESIA): PRELIMINARY VIRTUAL ASSESSMENT TEAM (P-VAT) REPORT

A series of tsunami waves hit the shorelines of Sunda Strait, Indonesia, without warning around 9:30 PM local time on Saturday, December 22nd, 2018. The Sunda Strait Tsunami was almost certainly the result of a southwest flank collapse on the Anak Krakatau volcano, which has been erupting continuously since June 2018. Satellite imagery confirms a significant loss of land on the southwest side of the volcanic cone, while tsunami simulations confirm that this event would have resulted in waves similar to what was observed along the shores of Sunda Strait. The primary damage to built infrastructure consisted of complete destruction of light-framed timber and bamboo houses and kiosks along the shoreline. Unreinforced masonry buildings in close proximity to the shoreline experienced partial to complete collapse. Damage did not extend more than a few rows of buildings from the coastline, though this often included the coastal road that ran close to the shore. Floating debris from damaged buildings and vehicles is suspected to have increased damage to adjacent buildings through debris damming and impact loads. Fortunately, debris and fallen utility lines on the coastal road were cleared quickly to allow access for emergency response teams. Utility lines were being reinstated within days of the tsunami. This Preliminary Virtual Assessment Team (P-VAT) Report overviews the hazard characteristics and coastal impacts associated with this event by collocating publicly-reported information. As the primary product of StEER’s response to this event, this P-VAT Report will help to inform and support other research teams seeking to learn from this disaster.