Abstract:
Tsunamis are being more frequent in and around Pacific Ocean but it is also observed frequently in South East Asia, Japan and western coast of North and South America. Most often the release and transfer of energy cause it during a tectonic type of an earthquake as being the case in December 26, 2004 destructive tsunami. Although large earthquakes along the Makran Subduction Zone are infrequent, the potential for the generation of destructive tsunami along the Makran coast of Pakistan and in the Northern Arabian Sea cannot be ruled out. This region has already suffered a devastating earthquake triggered tsunami in November 28, 1945 that caused more than 4000 deaths and a great loss of property not only along the Makran coast of Pakistan but also along the coasts of Western India, Iran and Oman. Tectonic collisions are actively taking place along the Southern and Southeastern boundary of Eurasian plate and entire Indian plate and adjacent micro plates which are responsible for October 8, 2005 earthquake in Northern Pakistan. Transfer of tectonic stress to other stress loaded tectonic regions can cause tsunamigenic earthquake in the Northern part of Arabian Sea along the coast of Makran. Study shows that Oman oceanic lithosphere is undergoing Subduction and it is moving northward beneath the Iranian micro-plate at a very shallow angle at very high rate. This activity is causing uplift, which is turning Makran Coast both in Baluchistan and Sindh provinces into a very densely faulted belt. This tectonic activity has also created offshore thrust faults and as in the past, large devastating tsunami is always a possibility along major faults in east Makran region, near Karachi as well as along the western end of the subduction zone. Moreover, this subduction has accumulated thick sediments particularly along the Eastern Sindh region near the Indus River delta. As submarine landslides can also cause tsunami, this region has the potential to cause a large submarine tsunamigenic landslide. Submarine landslides don’t need an earthquake of high magnitude; even smaller magnitudes can also trigger such under water landslides causing tsunami. Current study is based on the propagation of tsunami to the 50 m depth of water; it does not cover the tsunami run-up and its inundation on the coasts. The areas of focus for this study were coastal cities of Pakistan mainly Karachi, Ormara, Pasni, and Gawadar. The selected locations are very important because of the fact that Karachi is the mega city of Pakistan, Ormara is the Naval base of Pakistan Navy, Pasni has suffered heavy amount of destruction in 1945 and Gawadar due to the fact that it is Pakistan’s upcoming most important port city. Expected tsunami wave height and its arrival time at the coast as well as potential threat to these cities have been studied. AVINAMI software has been used for simulation and modeling of tsunami in this study.
Page(s):
25-40
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Meterology, Volume: 4, Issue: 7, Year: 2007