The 22 December 2018 Mount Anak Krakatau volcanogenic tsunami on Sunda Strait coasts, Indonesia: tsunami and damage characteristics

Abstract

Abstract. On 22 December 2018, a tsunami was generated from the Mount Anak Krakatau area that was caused by volcanic flank failures. The tsunami had severe impacts on the western coast of Banten and the southern coasts of Lampung in Indonesia. A series of surveys to measure the impacts of the tsunami was started 3 d after the tsunami and lasted for 10 d. Immediate investigations allowed the collection of relatively authentic images of the tsunami impacts before the clearing process started. This article investigates the impacts of the 2018 Sunda Strait tsunami on the affected areas and presents an analysis of the impacts of pure hydrodynamic tsunami forces on buildings. Impacts of the tsunami were expected to exhibit different characteristics than those found following the 2004 Indian Ocean tsunami in Aceh. Data were collected from 117 flow depths along the Banten and Lampung coasts. Furthermore, 98 buildings or houses were assessed for damage. Results of this study revealed that the flow depths were higher in Banten than in Lampung. Directions of the tsunami arrays created by the complex bathymetry around the strait caused these differences. Tsunami-induced damage to buildings was mostly the result of impact forces and drag forces. Damping forces could not be associated with the damage. The tsunami warning system in Indonesia should be extended to anticipate non-seismic tsunamis, such as landslides and volcanic processes driven by tsunamis. The lack of a tsunami warning during the first few minutes after the generation of the first wave led to a significant number of human casualties in both of the affected areas.

Characteristics of building fragility curves for seismic and non-seismic tsunamis: case studies of the 2018 Sunda Strait, 2018 Sulawesi-Palu and 2004 Indian Ocean tsunamis

“…However, few data points are available beyond 4.5 m in Sunda Strait area. Therefore, the damage probability uncertainty is greater upon this 445 value, hence the difference between our ds4-curve and the one produced by Syamsidik et al, 2020. https://doi.org/10.5194/nhess-2020-395 Preprint. Discussion started: 16 December 2020 c Author(s) 2020.…”

“…The subaerial/submarine landslide volume ranges from 0.15 to 0.30 km 3 (Grilli et al, 2019;Paris et al, 2020). It triggered a short wave period tsunami (~7 min) , which devastated the western coast of Banten and the southern coast of Lampung with a death toll of 437 (Heidarzadeh et al, 2020;National Agency for Disaster Management (BNPB), 2018; Syamsidik et al, 2020). Almost two months before this event, an unexpected tsunami struck Palu-Bay, on Sulawesi Island, claiming 2000 deaths and considerable loss property 55 (Association of Southeast Asian Nations (ASEAN)-Coordinating Centre for Humanitarian Assistance on disaster, 2018).…”

“…Here, we compare the completely damaged/washed away fragility curve for confined-masonry buildings to Syamsidik et al, 2020, who developed the curve as a function of observed flow depth for these buildings, as depicted in Fig. 13a.…”

Influence of Orientation and Arrangement of Structures on Tsunami Impact Forces: Numerical Investigation with Smoothed Particle Hydrodynamics

“…More recently, in 2018, the Palu-Indonesia tsunami and its subsequent widespread liquefaction caused severe damage to infrastructure, killing 2096 people with 1373 people reported as missing (Syamsidik et al 2019). In the same year, a volcanic-induced tsunami in Indonesia which was triggered by the Mount Anak Krakatau eruption also damaged a significant amount of structures, killed 437 people and injured more than 30,000 (Syamsidik et al 2020).…”

Characteristics of building fragility curves for seismic and non-seismic tsunamis: case studies of the 2018 Sunda Strait, 2018 Sulawesi–Palu, and 2004 Indian Ocean tsunamis

“…Moreover, a dozen coastal landslides were reported during field surveys and likely contributed to amplify tsunami waves (Arikawa et al, 2018;Muhari et al, 2018;Omira et al, 2019;Pakoksung et al, 2019). However, according to Ulrich et al (2019), those subaerial and submarine landslides may not be the only tsunami source as the Sulawesi earthquake rupture may have also induced a large portion of the tsunami waves.…”