Effects of Earthquake Shaking and Volcanic Activity on the Sediments of Lake Singkarak and Lake Maninjau in West Sumatra

Penulis: Katleen Wils, Mudrik R. Daryono; Nore Praet; Arianto Budi Santoso; Aan Dianto; Sabine Schmidt; Morgan Vervoort; Jyh-Jaan Huang; Edi Kusmanto; Purnama Suandhi; Danny H. Natawidjaja; Marc De Batist
Natural hazards such as earthquakes, volcanic activity, and heavy rainfall causing floods and debris avalanches are common phenomena in many tropical settings, including the island of Sumatra, located in the Indonesian archipelago. To enhance our understanding of the history of these often destructive events we study the sedimentary infill of two lakes in the Padang highlands, West Sumatra. This includes Lake Singkarak, a tectonically-formed lake located on a step-over of a major strike-slip fault system (the Sumatran Fault), and Lake Maninjau, a caldera lake. Both lakes are located at ~300 km from the Sunda subduction trench and surrounded by steep slopes and a chain of active volcanoes. Hence, considering their unique tectonic setting, these lakes may potentially record a wide range of natural hazards that affect the region. A combination of seismic-reflection profiles and short sediment cores revealed that both lakes indeed record various types of natural hazards, each with their own sedimentary response to a specific type of event. Lake Singkarak can be used to study past floods and major debris avalanches in addition to high-magnitude megathrust earthquakes, while traces of past intraplate earthquakes have been identified in both lakes. Furthermore, we argue that Lake Singkarak is an ideal recorder of volcanic activity in the region, while Lake Maninjau itself can pose a volcanic hazard to its surroundings as argued by potential activity of the volcano below.

Sedimentary Geology

No. Arsip : LIPI-20210107
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