Earthquake hazard assessment in the Momase region of Papua New Guinea

Abstract

Tectonism induced Tsunami, fire, landslide along with the tremor-triggered-liquefaction are the common hazards experienced worldwide. Such hazards often lead to collapse of built-up infrastructures like roads, bridges, buildings apart from inflicting heavy toll on human life and properties. Momase region of Papua New Guinea is one such vulnerable stretch where the appropriate planning is paramount in safeguarding the life and infrastructures. The study sought evaluation and assessments of the level of vulnerability to earthquakes in Momase region. The output can be used as a tool to assist in appropriate site selection that will minimize the earthquake damage risk and also to assist in better and appropriate future construction design or planning at a site. For the present study, application potentials of GIS and remote sensing are utilized to evaluate and assess possible earthquake hazard in the study region. The influence of soil and geology as the media responsible for aggravating or mollifying earthquake waves are underlined as input. These are the media that influence ferocity of shaking intensity leading to the destructions during an earthquake episode. Therefore, the site-soil geology and geomorphology are assessed and integrated within GIS environment coupled with seismicity data layers to evaluate and prepare liquefaction potential zones, followed by earthquake hazard zonation of the study area. Multi-criteria evaluation with analytical hierarchy process are adopted for this study. The technology involves preparing and assessing several contributing factors (thematic layers) that are assigned weightage and rankings, and finally normalizing the assigned weights and ranking. The spatial analysis tool in ArcGIS 10, the raster calculator, reclassify and weightage overlay tools were mainly employed in the study. The final output of LPZ and earthquake hazard zones were reclassified to ‘very high’, ‘high’, ‘moderate’, ‘low’ and ‘very low’ to indicate levels of hazard within a study region.