Abstract Database


Vitoria Maria de Lillia da Costa Oliveira
Supervisor: Tatsuya ITOI
Country: Timor-Leste

This dissertation examines the purpose of defining the seismic hazard level in Timor-Leste for seismic building codes based on past earthquakes and tectonic settings. The historical earthquake occurrences from 1960 to 2021 were collected from the United States Geological Survey (USGS) and the Institute of Geology and Petroleum (IPG) with a magnitude between 2 and 8.1 Richter Scala. Earthquake source zoning was based on the occurrences of historical earthquakes surrounding Timor-Leste, and the frequency magnitude distribution by using the Gutenberg-Richter recurrence law was estimated. The kernel density function has been used to modulate the probability distribution of hypocenter distance from different source zones. The simulation procedure was to determine peak ground acceleration using the Ground Motion Prediction equation adapted from Si et al, 1999. The result gave the seismic hazard curves, and a seismic hazard map plotted for the return period of 475 and 2500 years (10% and 2% exceedance in 50 years, respectively). The highest total hazard observed in the Atauro site was a very high hazard level with a PGA value of 440 gals and 209 gals, which was included in class V and class III, corresponding to a 2% and 10% probability of exceedance in 50 years. However, the smallest total hazard observed in the southern part of the Viqueque site was a low hazard level with a PGA value of 171 gals for a 2% probability of exceedance for 50 years also for 10% probability of exceedance for 50 years discovered in Viqueque, Lautem and RAEOA sites with the PGA value less than 100 gals.

Keywords: Timor-Leste, Earthquake Source Zones, Earthquake Parameters, PGA, Seismic Hazards