Seismic hazard analyses for North Java Offshore Indonesia using ISO 19901-2:2004

Abstract

Most offshore platforms in Indonesia use API RP 2A WSD as a guideline for designing earthquake-resistance offshore structures. However, this guideline does not explicitly state the return periods and the procedures for developing the designed response spectrum for used in seismic design. The procedures are described in more detail in ISO 19901-2 which stated explicitly requirement design parameter of 1.0s oscillator period and for a 0.2s oscillator period for a 1000-years return period of the earthquake. The paper presented a development of seismic hazard maps for 1.000 years return period for North Java Offshore Indonesia. The seismic hazard maps were modeled by the USGS PSHA program based on probabilistic concepts. The seismic sources used in the analyses were based on the latest researches published by National Center for Earthquake Studies (PuSGeN) in 2017. The study reveals that, generally, North Java Offshore Indonesia can be categorized as seismic zone 1 and 2 and East Madura as seismic zone 3 in accordance to ISO 19901-2.