Field Survey of Tsunami Heights and Runups Following the 22 December 2018 Anak Krakatau Volcano Tsunami, Indonesia
- PDF / 7,083,411 Bytes
- 19 Pages / 547.087 x 737.008 pts Page_size
- 57 Downloads / 177 Views
Pure and Applied Geophysics
Field Survey of Tsunami Heights and Runups Following the 22 December 2018 Anak Krakatau Volcano Tsunami, Indonesia MOHAMMAD HEIDARZADEH,1
PURNA SULASTYA PUTRA,2 SEPTRIONO HARI NUGROHO,2 1 DOUD BEN ZUBAIR RASHID
Abstract—The 22 December 2018 Anak Karakatau tsunami in Indonesia was a rare event in that few instrumental records existed of tsunamis generated by volcanic sources before this event. The tsunami, which left a death toll of 437, is of global importance as it provides opportunities to develop knowledge on generation, propagation and coastal effects of volcanic tsunamis. Here, we report results of field surveys along the coast of the Sunda Strait, Indonesia to study tsunami wave heights and coastal damage. We surveyed 29 locations and measured ranges of tsunami runup from 0.9 to 5.2 m, tsunami heights from 1.4 to 6.3 m, flow depths from 0.2 m to 3.0 m and inundation distances from 18 to 212 m. The largest tsunami heights and concentration of damage and fatalities occurred on the western shore of Java from Tanjung Lesung to Sumur. The largest cluster of fatalities occurred at Tanjung Lesung, where more than 50 people died while attending an outdoor music being held at the shoreline. The tsunami runup and tsunami height in Tanjung Lesung were 4.0 and 2.9–3.8 m, respectively. We believe this tragedy could have been avoided if the event organizers were more aware of the hazard posed by the Anak Krakatau volcano, as it had been actively erupting for several months prior to the tsunami, and simply moved the concert stage 100 m inland. Many of the locations surveyed demonstrated a similar pattern where the majority of casualties and destruction occurred within 100 m of the coast; in several locations, lives were saved where buildings were located at least this distance inland. The significant damage and numerous deaths which occurred in Sumur, despite the moderate tsunami height of 2.3–2.5 m, can be attributed to the extremely low-lying coastal land there. Flow depth in Sumur was 0.9–2.0 m. During our field surveys, nearly one year after the event, we noted that some of the damaged buildings were being rebuilt in the same locations just 10–30 m from the shoreline. We question this practice since the new buildings could be at the same tsunami risk as those damaged in the 2018 event. Keywords: Tsunami, Anak Krakatau Volcano, Sunda Strait, field surveys, tsunami simulations.
1
Department of Civil and Environmental Engineering, Brunel University London, Uxbridge UB8 3PH, UK. E-mail: [email protected] 2 Research Center for Geotechnology, Indonesian Institute of Sciences (LIPI), 40135 Bandung, Indonesia. E-mail: [email protected]
and
1. Introduction The eruption of the Anak Krakatau Volcano (AKV) (Fig. 1a) on 22 December 2018 resulted in a deadly tsunami along the coast of Sunda Strait, Indonesia (Muhari et al., 2019; Putra et al., 2020). Approximately 228 m of the top part of the AKV slid into the sea as a result of the eruption (Fig. 1b). The 2018 Anak Krakatau Tsunami (
Data Loading...
