Recent development of seismic source and hazard maps of Indonesia for earthquake resistant design

The main cause of casualties from earthquakes in Indonesia arises from building and infrastructure failures due to non-compliance with seismic codes, a lack of understanding of local hazards, and additional complexity in seismic risks. Strengthening earthquake-resistant designs for buildings and infrastructure is therefore crucial. Efforts towards disaster risk reduction in Indonesia have been notable. The Ministry of Public Works and Housing (PUPR) has developed six Hazard Maps of Indonesia and consistently enhanced Building and Infrastructure Codes. The initial seismic hazard map was developed in 1966, followed by updates in 1970,1983, 2002, 2010, and 2017. The National Center for Earthquake Studies (PuSGeN), established and supported by the Ministry, serves as a collaborative hub for Indonesia’s earthquake scientists and engineers, dedicated to refining data for national seismic sources and hazard maps and formulating earthquake resistance codes. PuSGeN has engaged in extensive partnerships with United States Geological Survey (USGS), the Australian Department of Foreign Affairs & Trade (DFAT), and the Global Earthquake Model Foundation (GEM). In 2017, PuSGeN released the most recent seismic sources and hazard maps, incorporating results from recent active fault studies, employing geological, geophysical, and geodetic observations, along with a new comprehensive earthquake catalog. This involved relocating hypocenters in a three-dimensional velocity model and modeling seismic source zones using the 2008-USGS and OpenQuake Engine software. Subsequently, impactful and destructive earthquakes occurred after the latest maps were published, providing new insights into earthquake sources. Substantial research has been conducted on active faults near major cities, including a potential active fault near the New Capital of Indonesia. Therefore, an ongoing process to update the 2017 maps is underway to better capture potential earthquake hazards. The work will consider the latest significant earthquakes, recent findings on active faults, new data, updated GMPEs, and advanced methodologies for seismic hazard mapping, all aimed at supporting earthquakeresistant design in Indonesia.