Identification Fault Characteristic in Southern Sulawesi by Focal Mechanism

Abstract

Sulawesi has complex tectonic, signed by fault like Palu-Koro Fault, Walennae Fault, Matano Fault, Batui Fault and others. Mostly fault located on Southern Sulawesi and it caused earthquake in Southern Sulawesi. The aim at this study is to learn fault characteristic by focal mechanisms in Southern Sulawesi. Focal mechanism is method to analyze movement mechanism based on first polarity of earthquake P-wave to determine fault caused by earthquake fault which caused earthquake. In this study is located on Southern Sulawesi with 2°26’ - 6°50’ S and 118° -123°50’ E during 1976 – 2016 from Global-CMT. The hypocenter plotted to identify location of the earthquake. The fault parameter, such as strike, dip and slip plotted to interpret focal mechanism of fault caused earthquake. The data plotted by GMT to get distribution focal mechanism on Southern Sulawesi which shown 46 beach-balls. For interpretation, it divided into 3 regions; region I show oblique-reverse fault related to Makassar Thrust. Region II show left-strike-slip fault related to Matano Fault activity. Region I shows Paternoster fault and earthquake by sea spreading at Bone Gulf; Walennae Fault with strike-slip fault activity. Region III the most complex region show normal fault related to Tolo Fault activity. Region III shows Kolaka fault with strike-slip fault activity and earthquake by interaction between micro-continent observed as oblique-reverse fault activity.. The focal mechanism in this study effectively to observe the fault activity which can be used as guided for earthquake mitigation.