Review of the Morphological changes of Anak Krakatau before and after 2018 Eruption using Drone
Wilfridus F. S. Banggur (a*), Aditya Pratama (a), Taufik Ismail (a),(b), Dini Nurfiani (a), MN Kartadinata (c), Devy Kamil Syahbana (c), Deni Mardiono (c), Estu Kriswati (a), Philipson Bani (d), Muhammad Zain Tuakia (e)

a) Center of Geological Disaster Research, Indonesia Agency of Research and Innovation, Bandung 40135, Indonesia
*wilf001[at]brin.go.id
b) Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Bandung 40132, Indonesia
c) Centre for Volcanology and Geological Hazard Mitigation, Bandung 40122, Indonesia
d) Laboratoire des Geosciences et Physique de la matiere condens ee, Universit e de la Nouvelle Cal edonie, BP 4477, Noumea, New Caledonia, France
e) Research Center for Geological Resources, National Research, and Innovation Agency (BRIN), Bandung 40135, Indonesia

Abstract

We have taken aerial photo data using drones on Anak Krakatau in 2013, 2019, 2020 and 2021. The drone used is a quadcopter, flown at an altitude of 250 meters, with a north-south and east-west direction over Mount Anak Krakatau. Changes in the morphology of Anak Krakatau occurred so quickly as its volcanic activity never stopped. Its pyroclastic cone in 2013 reached a height of 334 meters with a coastline circumference of 6.8 km. The circumference of the pyroclastic cone calculated from the traces of the old crater wall has a volume of 31971 m3. As secondary data to determine changes in morphology between the 2013 and 2018 eruptions before the eruption and the tsunami, we used satellite imagery, seismic recordings, to find out the volcanic activity that affected the morphological changes. The December 2018 eruption and tsunami have changed the morphology of Anak Krakatau. Pyroclastic cones and lava flow products that dominate in the south to west have collapsed and become a crater opening with a diameter of 400 meters, level with sea level. The coastline has increased in circumference to 7.2 km with a height of 156 meters. The body of Anak Karakatu has experienced an addition to the coastline, especially on the South, East and North sides. This happened due to the eruption and tsunami accompanied by avalanches during the December 2018 eruption. During the 2020 and 2021 eruption periods, the coastline has not changed. This period was marked by the growth of a pyroclastic cone in the crater that had formed previously during the 2019 eruption. The pyroclastic cone was opened to the southwest by lava flows that flowed westward as far as 600 meters.

Keywords: Anak Krakatau- morphology changes- drone.

Topic: Solid Earth Sciences