Geochemical Approach for Anak Krakatau Eruption Patterns
Windi Anarta Draniswari 1, Aditya Pratama 1, Dini Nurfiani 1, Taufik Ismail 1,2, Wilfridus Ferdinando Supriyadi Banggur 1, Putu Billy Suryanata 1,3, Muhammad Zain Tuakia 4

1 Center of Geological Disaster Research, Indonesia Agency of Research and Innovation, Bandung 40135, Indonesia
2 Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Bandung 40132, Indonesia
3 Faculty of Mining and Petroleum Engineering, Bandung Institute of Technology, Bandung 40132, Indonesia
4 Research Center for Geological Resources, National Research, and Innovation Agency (BRIN), Bandung 40135, Indonesia

Abstract

Mt. Anak Krakatau is one of the most active volcanoes located in Sunda Strait. It is vital to understand the temporal and chemical evolution of Mt. Anak Krakatau in order to forecast a future eruption. This paper aims to analyze the trend of eruption probabilities through a statistical review. We use the rock geochemistry database and eruption histories to describe the link between magma evolution and volcano eruption. The contributions of each parameter to the repose length were examined through the log-likelihood. The statistical analysis reveals that the Volcano Eruption Index (VEI) and the time of the eruption are correlated with the chemical composition of the magma. The eruption could alter the dynamics of the magma chamber during the repose period and be recorded as the petrology and geochemical characteristic of rocks. The variability of the geochemical concentration of SiO2, TiO2, Al2O3, or MgO correlates with the repose length and the mixing process in the magma chamber. This finding can be used to reinforce the petrology and geochemistry data to identify the possible composition trends and the behavior of the volcano. Hence there is a limitation for eruption forecasting related to the morphological changes and displacement of the eruption vent.

Keywords: Anak Krakatau, geochemistry, eruption

Topic: EARTH, ATMOSPHERIC, AND SPACE SCIENCE