Study of Bathymetry and Seabed Morphology Changes around Anak Krakatau Waters of 2018 Post-Eruption

Abstract

Anak Krakatau is an active volcanic mountain located in the Sunda Strait, Indonesia. On December 22, 2018, this mountain erupted and the flank collapses off into the water. This changes the bathymetry and morphology of the seabed around the waters of Anak Krakatau volcano. This study uses bathymetry data surrounding the Anak Krakatau waters from the Indonesian Navy Hydrographic and Oceanographic Center (PUSHIDROSAL) in 2016 and 2019. The data were obtained by survey using Echosounder Multibeam System MBES EM2040 and EM302. By means of surface analysis method (hillshade), the data were process to observe the bathymetry and seabed morphology changes around the Anak Krakatau volcano waters by the eruption. The results of bathymetry data processing show a depth change of about 25 m, with the lowest value in 2016 ranging from -250,328 m and in 2019 ranging from -226.12 m. The average value of the slope of the seabed in 2016 was 5.31° and 4.98° in 2019.