A.M. Julius¹ , B. Sunardi² , M. Muzli²

¹National Seismological Center, Meterological and Geophysical Agency
²Center of Research and Development, Meterological and Geophysical Agency

Abstract:

For buildings most scientists assume that the maximum amplitude and longest duration of strong motion are in the highest structures. Contrary, this study used three waveform of events which were recorded on an accelerrographs array in a 12-store building in Jakarta. Those are the M6.5 Kebumen, M5.6 Pandeglang, and M4.7 Lebak earthquakes. It shows that the effective duration of the M6.5 Kebumen is shortest and high amplitude is in the highest structure. But the M5.6 Pandeglang, and M4.7 Lebak are in different. Based on source mechanism data, seismic waves of the M6.5 Kebumen directly traveled to Jakarta, in one direction on strike. Ruptures release high amplitude and short duration of strong motion on forward direction or contrary for strike indirectly. According to this study, it is shown that the object of energy compensation of M5.6 Pandeglang and M4.7 Lebak is on duration, whereas the object of energy compensation of M6.5 Kebumen is on amplitude. This study was strengthened by similar method and result on the Aceh Sumatra earthquake.