Semi-probabilistic Method in Analysing Kendeng Fault Earthquake Hazard in Surabaya, East Java

Abstract

Surabaya is one of the cities in Indonesia which is prone to earthquakes. This condition is caused by the megathrust zone located in southern Java. In addition, there is an active fault that passes through East Java, namely the Kendeng fault, which to be the source of underground earthquakes. The part of Kendeng Fault that is situated near Surabaya is classified as the Surabaya segment and Waru segment. Based on this condition, research was carried out to analyze the earthquake hazard caused by Kendeng Fault in Surabaya city. A semi-probabilistic method is used in this research, as it can calculate the Peak Ground Acceleration (PGA) and earthquake intensity by considering the range from the measurement point to every point on the fault. The PGA measurement is using the equation of attenuation function. USGS Vs30 data, East Java Province base map, and Surabaya geological map are the data that were used to support the research. The result of earthquake hazard analysis gives the highest ground acceleration potential region is located in the north-western Surabaya subdistricts, this includes Sambikerep and Lakarsantri subdistricts. The high value of PGA and earthquake intensity is strongly affected by the short distance to the earthquake source.