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Where could the next tsunami on the Makran coast of Iran and Pakistan come from? With Amin Rashidi (University of Tehran), Mohammad Mokhtari, Mehdi Masoodi, Parvaneh Faridi and Sara Kiani, we reviewed the research (Journal of Seismology and Earthquake Engineering, 2024). 🧵 #Tsunami

2/ In the Makran, the Arabian plate sinks under Eurasia at about 20 mm a year. A wedge of sediment scraped off the sinking plate is 350 to 400 km wide, and the sediment is up to 7 km thick. Its earthquakes are fewer than in the zones on either side, yet it has made tsunamis.

4/ Most Makran tsunami studies are computer simulations: 63% of them. Only 9% study the traces that past tsunamis left on the coast, such as sand layers and boulders. Such traces point to a possible tsunami in western Makran about 1,000 years ago.

5/ The great earthquake on the plate boundary is not the only source. Our review gathers the others: splay faults that branch up from it, normal faults that reach down to it, landslides on steep undersea slopes, and possibly storms, which can drive a meteotsunami.

6/ Landslides appear to be the second most important source. In 100 simulated landslide tsunamis off western Makran, Chabahar in Iran and Muscat in Oman stood out as the most exposed. No meteotsunami is on record in the Gulf of Oman, but cyclones reach it, like Gonu in 2007.