Deterministic and probabilistic seismic hazard analyses in Thailand and adjacent areas using active fault data

Santi Pailoplee,Punya Charusiri,Yuichi Sugiyama

doi:10.1186/bf03352984

Abstract

AbstractSeismic hazards in Thailand and adjacent areas were analyzed mainly on the basis of geological fault data. We identified 55 active fault zones using remote-sensing data on earthquake source parameters derived from both active fault data and earthquake catalogues. We selected strong ground-motion attenuation models by comparing the application of several candidate models with strong ground-motion data recorded in Thailand. Both deterministic (DSHA) and probabilistic (PSHA) approaches were used—DSHA for the design of critical construction and PSHA for the design of non-critical construction. We also applied two frequency-magnitude models in the PSHA approach: the exponential magnitude distribution model and the characteristic earthquake model. The seismic hazard results obtained using the deterministic and probabilistic approaches are not equivalent. The resulting DSHA map reveals extremely high seismic hazard levels in some areas of Thailand and in surrounding countries, while the PSHA map reveals a seismic hazard distribution similar to that of the DSHA but with lower seismic hazard levels. The areas of high seismic hazard include countries neighboring Thailand, such as Myanmar, Laos, Vietnam, and Indonesia (Sumatra Island), and areas within Thailand itself, primarily those areas in northern, western, and southern Thailand that are dominated by active fault zones.

Highlights

There are a number of active fault systems in northern, western, and southern Thailand (e.g., Fenton et al, 2003; Charusiri et al, 2004; Wong et al, 2005) (Fig. 1(a))
There have been few seismic hazard investigations that have focused on Thailand
The main objectives of this study were to reveal a worst case scenario for critical seismic hazards in the study area using the deterministic seismic hazard analysis (DSHA) approach and to investigate the sensitivity of probabilistic seismic hazard analysis (PSHA) for a non-critical construction plan. We suggest that these complementary DSHA and PSHA approaches can provide a seismic hazard assessment that is more detailed and up-to-date than that currently available

Summary

Introduction

There are a number of active fault systems in northern, western, and southern Thailand (e.g., Fenton et al, 2003; Charusiri et al, 2004; Wong et al, 2005) (Fig. 1(a)). Warnitchai and Lisantono (1996) and Palasri (2006) used the probabilistic approach to seismic hazard analysis by using recent seismicity data (i.e., from earthquake catalogues). Their results, may be characterized by a number of limitations because of the short history of instrumental recordings of Copyright c The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences; TERRAPUB

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Methods

Conclusion