Geophysical observation to several sites around Pulau Baai Port, Bengkulu City, Indonesia

Abstract

Pulau Baai Port is known as the important area in Bengkulu City. The port is also the main port that supports the economic aspect in Bengkulu Province. This study is conducted to observe local site conditions in several areas around Pulau Baai Port. The areas are very important in supporting the function of Pulau Baai Port. Therefore, the understanding of local site conditions in the surrounding regions is needed. This study was initiated by performing a geophysical measurement using a multichannel analysis of surface waves (MASW) method. Measurements were performed by using 24 geophone channels to obtain surface waves. Data processing is conducted by plotting phase velocity corresponding to the frequency. Furthermore, the shear wave velocity (Vs) profile and the time-average of shear wave velocity for the first 30 m depth (Vs30) are presented. Vs30 from measurements is compared to Vs30 from United States Geological Survey (USGS). In general, the investigated sites are categorized as Site Class D. It indicates that the sites are more vulnerable to undergo seismic damage. The results also show that Vs30 from measurements are relatively consistent with Vs30 from USGS. Generally, this study could bring a recommendation to the government in considering seismic hazard impact for Pulau Baai Port development.