Karachi is the most populated city in Pakistan with around 24,000,000 inhabitants – just as many as Australia. Since many years a nuclear power plant (NPP) is located just a few miles outside the city at the shore. Ongoing work on new reactors with Chinese help has recently sparked outrage and media coverage. Concerns are that any accidents at the NPP might have dramatic consequences and threaten millions of people. I searched the recent scientific literature on seismic and tsunami hazard for Karachi…
- In 2013, an onshore earthquake in Pakistan triggered a submarine slide that caused small tsunami in the Indian ocean. Karachi was not affected. Hoffmann, G., Al-Yahyai, S., Naeem, G., Kociok, M., & Grützner, C. (2014). An Indian Ocean tsunami triggered remotely by an onshore earthquake in Balochistan, Pakistan. Geology, 42(10), 883-886.
- In 1945, a magnitude 8 earthquake occurred at the Makran subduction zone and triggered a fatal tsunami. Waves in Karachi were as high as 2 m. About 200 people died in the Karachi District, damage to houses and infrastructure. Hoffmann, G., Rupprechter, M., Balushi, N. A., Grützner, C., & Reicherter, K. (2013). The impact of the 1945 Makran tsunami along the coastlines of the Arabian Sea (Northern Indian Ocean)–a review. Zeitschrift für Geomorphologie, Supplementary Issues, 57(4), 257-277.
- In a series of interviews, elders recall the 1945 tsunami wave impact. Kakar, D. M., Naeem, G., Usman, A., Hasan, H., Lohdi, H. A., Srinivasalu, S., … & Atwater, B. F. (2014). Elders Recall an Earlier Tsunami on Indian Ocean Shores. Eos, Transactions American Geophysical Union, 95(51), 485-486.
- At least five historical tsunamis occurred in the Makran Subduction Zone between 326 BC and 1945. “The results of the run-up modeling reveal that a large earthquake and tsunami in the MSZ is capable of producing considerable run-up heights in the far field.” Heidarzadeh, M., Pirooz, M. D., Zaker, N. H., Yalciner, A. C., Mokhtari, M., & Esmaeily, A. (2008). Historical tsunami in the Makran Subduction Zone off the southern coasts of Iran and Pakistan and results of numerical modeling. Ocean Engineering, 35(8), 774-786.
- Extreme flooding events occurred in the Arabian Sea in the Late Holocene: Hoffmann, G., Grützner, C., Reicherter, K., & Preusser, F. (2014). Geo-archaeological evidence for a Holocene extreme flooding event within the Arabian Sea (Ras al Hadd, Oman). Quaternary Science Reviews.
- “The city of Karachi […] sits close to a plate boundary and within reach of earthquakes on numerous tectonically active structures surrounding the city. […] Yet with a short historical record, limited instrumental seismic data, and little geological or geodetic constraint on slip rates, seismic hazard in Karachi is poorly characterized.” Bilham, R., Lodi, S., Hough, S., Bukhary, S., Khan, A. M., & Rafeeqi, S. F. A. (2007). Seismic hazard in Karachi, Pakistan: uncertain past, uncertain future. Seismological Research Letters, 78(6), 601-613.
All these studies make one thing clear: There’s a lack of studies. As Bilham et al. (2007) point out, very little is known about the faults around the city and paleosesimological studies are rare. We don’t know much about slip rates, recurrence intervalls, last earthquakes, maximum magnitudes etc. Even the paleo-earthquake information on the Makran Subduction Zone is sparse. As far as I know, there are no paleo-tsunami studies for Karachi and its vicinity at all…
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