Deaggregation of Seismic Hazard for Two Ports in Mumbai Metropolitan Region

Abstract

Sea ports play an important role in the growth of any country's economy. To reduce devastation due to seismicity, suitable site specific seismic hazard analysis of ports is a must. In the present paper, site-specific seismic hazard analysis of two important ports - namely, Mumbai port and Jawaharlal Nehru port - which helped Mumbai to become the financial capital of India, has been evaluated probabilistically. This study develops site-specific seismic hazard curves and uniform hazard response spectra for three different probabilities of exceedance (50%, 10%, and 2%) in a span of 50 years. The epistemic uncertainty in hazard estimation was accounted for by employing seven different ground motion prediction equations developed for worldwide, shallow, crustal, intra-plate environments. The generated response spectrum was compared with that specified by Indian seismic code (IS:1893-Part 1, 2002) for rock sites. Seismic hazard results were deaggregated for three different probabilities to understand the relative contributions of earthquake sources in terms of magnitude and distance. For both ports, the hazard is observed to be at equal distance with different magnitudes for all levels of probability. Also, the larger earthquakes were observed to contribute more significantly to seismic hazard for longer periods for the two ports in the Mumbai metropolitan region.