SEDIMENTARY DEPOSITS STUDY OF THE 2006 JAVA TSUNAMI IN PANGANDARAN, WEST JAVA

• Main Author: MAEMUNAH (NIM : 22411304), IMUN
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28014
• Institution: Institut Teknologi Bandung

<p align="justify">2006 Java tsunami deposits study were conducted in Pangandaran area which focused at Karapyak and Madasari regions. The research consists of field surveys and laboratory analysis. Twenty eight shallow pits in five transects at Karapyak and Madasari has been excavated. These pits are relatively parallel to the tsunami waves which was confirmed by the tsunami eyewitnesses. Tracks were made from the shoreline inland along 273 m. <br /> <br /> Macroscopic description, establish cross-section of lithology and thickness of tsunami deposits and laboratory analysis in the form of grain size analysis and identification of microfauna has been completed to determine the characteristics of 2006 Java tsunami deposits. Identification characteristics of The 2006 Java Tsunami deposits refers to the characteristics of tsunami deposits by Morton et al., 2007. <br /> <br /> The 2006 Java tsunami deposits found in the study area are located relatively shallow from the surface. These deposits are partially covered either by mud cap or shrubs. Sediment thickness ranging from 0.2-25 cm. Tsunami deposits found at 38 m from the shoreline with a thickness of 3-7 cm to a distance of 273 m from the shoreline with 0.2 – 3 cm thickness. The maximum tsunami deposits thickness of 25 cm were found on transect M3 which located 84 m from the shoreline. <br /> <br /> In general, the tsunami deposits characteristics are bright grey – brownish grey, with grain sizes from gravel to coarse silt (Wentworth grade scale). A thin layer of clay is also found within the tsunami deposits, partially structured graded bedding and partly non graded, moderatly-poorly sorted, the thickness changes of tsunami deposits have two tendencies which became thin inland and relatively constant. There are rip-up clasts, contact with buried soil partly erosional structure and partly abruptly. Within the tsunami deposits, we also found fractions of mussel shells and particles imbrication leading seaward and landward. <br /> <br /> Tsunami deposits grain sizes are getting finer upward. It also getting finer landward. Microfauna Amphistegina lessonii d'Orbigny and Elphidium macellum became the pointer. <p align="justify">