Tsunami flow depth measured at a house near Anyer of Banten after the December 22, 2018. Measured by TDMRC on December 25, 2018.

The 2018 Sunda Strait Tsunami Impacts Assessment

On December 22 2018, around 09.10 PM local time, a tsunami struck coastal areas of Banten and South Lampung. The tsunami was believed to be triggered by Anak Krakatoa Volcano Eruption. Until this brief report was released, at least 430 lives had been reported dead and hundreds more were still missing. A tsunami generated from a volcano eruption process is considered a rare event. Our understanding of its mechanisms and impacts is still limited. Up to now, it is still difficult to exactly tell what type(s) of mechanism led to the December 22, 2018 event. Although it is almost certain it came from the Krakatoa complex, lack of possible direct access to the source at the moment has hindered us from explaining the process. Several institutions have estimated the source based on comparison of aerial images of the Mt. Anak Krakatoa, before and after the tsunami. Information gathered from this event could benefit efforts to mitigate impacts of tsunami in the future.

Tsunami and Disaster Mitigation Research Center (TDMRC) of Syiah Kuala University has dispatched a small group led by Dr. Benazir to conduct a rapid assessment on impacts of tsunami around Banten and southern part of Lampung. The team members are Dr. Syamsidik and Mumtaz Luthfi, ST. (Dr. Syamsidik will later join this team in Lampung).  The objective of sending the team at the earlier stage of the post-tsunami event is to reveal the impacts of the tsunami on the coastal area by measuring tsunami flow depths, heights, direction, and its impacts on structures. The team has been in the field since day 3 after the event.

Tsunami flow depth measured at a house near Anyer of Banten after the December 22, 2018. Measured by TDMRC on December 25, 2018.
Tsunami flow depth measured at a house near Anyer of Banten after the December 22, 2018. Measured by TDMRC on December 25, 2018.
Tsunami flow direction indicated by vegetation in the affected area in Banten (measured Dec 25, 2018).
Tsunami flow direction indicated by vegetation in the affected area in Banten (measured Dec 25, 2018).

 

Unlike the previous survey performed by TDMRC Unsyiah in Palu bay following the September 28, 2018 earthquake-tsunami, the impacts measured from the Sunda Strait Tsunami Assessment will mainly be considered from tsunami forces. In Palu case, the results were mixed between earthquake and disaster, as well as liquefaction in some areas. Therefore, the survey in Sunda Strait is expected to generate pure tsunami impact results.

Impacts of the Sunda Strait Tsunami on a Coastal Village in Labuan, Banten (captured on Dec 26, 2018).
Impacts of the Sunda Strait Tsunami on a Coastal Village in Labuan, Banten (captured on Dec 26, 2018).
Damages due to impacts of the tsunami on buildings.
Damages due to impacts of the tsunami on buildings.

Until this report was released, a large area around Anyer, Labuan, and Tanjung Lesung were still deserted by local people. The people seek shelters at areas away from the coast.  This was resulted from a recent warning released by the Authority stating that the Child of Krakatoa is still active to erupt and still poses danger to the local community. TDMRC team takes this information seriously and remain in high alert for the situation.

This assessment is part of Partnership Enhanced Engagement in Research (PEER) USAID cycle 5 with the title of the research “Incorporating climate change induced sea level rise information into coastal cities’ preparedness toward coastal hazards”(#5-395). The Principal Investigator is Dr. Syamsidik from Tsunami Research Cluster of TDMRC Unsyiah.

Impacts of the tsunami on a hotel complex where the Seventeen Band performed their last show before they were struck by the tsunami.
Impacts of the tsunami on a hotel complex where the Seventeen Band performed their last show before they were struck by the tsunami.
An aerial Image at a village in Anyer three days after the tsunami hit this area.
An aerial Image at a village in Anyer three days after the tsunami hit this area.

The team is committed to provide all the information gathered from this survey to public when they are ready. Further information regarding this survey could be retrieved from TDMRC of Syiah Kuala University or email at benazir[at]tdmrc.org. Updates from this survey will be given when the team reaches Southern Lampung,  the other side of the survey area.