Simulation of tsunami generation, propagation and run-up in the western Makran, Part 1: Simulation of the generation


1 Ph.D. Student, Department of Earth Physics, Institute of Geophysics, University of Tehran, Iran

2 Associate Professor, Department of Earth Physics, Institute of Geophysics, University of Tehran, Iran

3 Assistant Professor, Geoscience Division, Research Institute of Petroleum Industry (RIPI), Tehran , Iran


Tsunami is an oceanic gravity wave generated by the displacement of huge volumes of water. There are three main types of disturbances: underwater earthquakes, submarine landslides and sudden earth surface movements adjacent to the ocean (volcanoes, meteorites, rock falls, sub-aerial landslides and ship sinking). Most tsunamis are caused by large shallow earthquakes in subduction zones (Satake and Tanioka, 1999). Sumatra–Andaman (2004) and Honshu, Japan (2011) tsunami events and following widespread damages and tragic consequences demonstrated the need of worldwide attention, awareness and preparedness for tsunami hazard mitigation. While the world draws its attention to tsunamis in the Indian Ocean, further attention is increased in the eastern areas of the Indian Ocean near Indonesia. Western Makran is located in the northwestern Indian Ocean basin. It has received less attention as a potential tsunamigenic zone. The Makran region is a 1000-km section of the Eurasian-Arabian plate boundary and located offshore Pakistan in the northwestern Indian Ocean where the oceanic crust of Arabian plate is being subducted beneath Eurasian plate since the Early Cretaceous along a north dipping subduction zone (Byrne et al., 1992; Smith et al., 2013). Following the great earthquake in Pasni-Ormara on 1945.11.27, Mw=8.1 (Byrne et aL, 1992), the coastline uplifted by about 2 m (Page et al., 1979). This event was accompanied by a significant regional tsunami, with run-up in the 5–10 m range which caused about 4000 deaths along the very sparsely populated Makran coast (Heck, 1947; Ambraseys and Melville, 1982; Okal and Synolakis, 2008). The Makran may be seismically segmented along its length into a western and an eastern segment, distinguished by different levels of seismicity (lower in the west). Moderate to large magnitude earthquakes are either related to the down going slab at intermediate depths or superficial in the eastern Makran (e.g. 1765, 1851 and 1945 earthquakes), while western Makran is marked with almost no seismicity in the coastal area at present but might have experienced a strong earthquake in 1483 (Byrne et al., 1992; Zarifi, 2006).
The lack of earthquakes for many years has increased the possibility of locking the western Makran segment. This means that, it could generate a potential tsunami event in the future that can threat the Gulf of Oman and the Makran coastlines. Because of the tsunamigenic potential of Makran subduction zone, also importance of strategic geographic location, financial role of Makran coast in Iran, accessibility to international waters, ability to communicate with other countries and its cultural, natural and historical tourism potential along with the establishment of ports and coastal and offshore installations in the region, tsunami can be a real threat. Consequently, it is indispensable to have accurate studies and estimates for tsunami risk mitigation. The aim of this study is to simulate tsunami generation in western Makran numerically for estimating the initial condition for tsunami propagation. Tsunami generation mechanism should be modeled as the first step in the process of tsunami modeling. The generation modeling problem should be studied geophysically and geologically, therefore it is a very important and vital stage in tsunami simulation. To estimate the static uplift of seafloor, we can use the fault models e.g., Okada (1985) and Mansinha and Smylie (1971) which are the analytical solution of deformation field caused by instantaneous rupture on an elastic finite fault plane. The theory was proposed originally by Mansinha and Smylie (1971) and then improved by Okada (1985). We need the fault parameters (Hypocenter (Latitude, Longitude and Depth), Length and Width of Fault Plane, Dislocation (Slip), Strike direction, Dip angle and Rake (slip) angle) to compute the deformation. A tsunami scenario with defined source parameters was constructed in the Gulf of Oman to compute the deformation field based on the Okada algorithm. The source model was based on Okal and Synolakis (2008) and Smith et al. (2013) with a length of 450 km, a width of 100 km and a dislocation of 10 m which has a moment magnitude (Mw) of 8.7. The result of this study represents the initial profile of the tsunami while including the uplift and subsidence in the study area. The earthquake scenario predicted maximum seafloor uplift of 3.5 m and maximum subsidence of 2.4 m. The deformation field covered an area from 23.5° N to 27.5° N and from 56° E to 63° E. The southern coastal areas of Iran and Pakistan experienced subsidence and the northern coastlines of Oman experienced uplift. The outcome can be used as the input in the simulation of tsunami propagation.


Main Subjects

Ambraseys, N. N. and Melville, C. P., 1982, A history of Persian earthquakes, Cambridge University Press, Cambridge, 1982.
Apel, E., Burgmann, R., Bannerjee, P. and Nagarajan, B., 2006, Geodetically constrained Indian plate motion and implications for plate boundary deformation, AGU, 85(52), Fall Meeting Supplement, Abstract T51B-1524.
Baba, T., 2003, Slip distributions of the 1944 Tonankai and 1946 Nankai earthquakes including the horizontal movement effect on tsunami generation, Frontier Research on Earth Evolution, 1, 213-218.
Bayer, R., Chery, J., Tatar, M., Vernant, Ph., Abbassi, M., Masson, F., Nilforoushan, F., Doerflinger, E., Regard, V. and Bellier, O., 2006, Active deformation in Zagros–Makran transition zone inferred from GPS measurements, Geophys. J. Int., 165, 373–381.
Byrne, D. E., Sykes, L. and Davis, D. M., 1992, Great thrust earthquakes and aseismic slip along the plate boundary of the Makran subduction zone, J. Geophys. Res., 97, 449–478.
Dunbar, P. K., Lockridge, P. A. and Whiteside, L. S., 2002, Catalog of Significant Earthquakes (2150 B.C.-1991 A.D.), National Oceanic and Atmospheric Administration Report.
Farhoudi, G. and Karig, D. E., 1977, Makran of Iran and Pakistan as an active arc system, Geology, 5, 664–668.
Geist, E. L., Titov, V. V. and Synolakis, C. E., 2006, Tsunami: wave of change, Scientific American, 294, 56-63.
Gutscher, M. A. and Westbrook, G. K., 2009, Great earthquakes in slow subduction, low-taper margins, in Subduction Zone Geodynamics, in: Lallemand S., Funiciello F. (Eds.), Subduction Zone Geodynamics, Springer-Verlag Berlin, Berlin, 119-133.
Hanks, T. C. and. Kanamori, H., 1979, A moment magnitude scale, J. Geophys. Res., 84, 2348–2350.
Heidarzadeh, M. and Satake, K., 2014, New Insights into the Source of the Makran Tsunami of 27 November 1945 from Tsunami Waveforms and Coastal Deformation Data, Pure Appl. Geophys., 172, nos. 3/4, 621–640.
Liu, P. L. F., Synolakis, C. E. and Yeh, H., 1991, Impressions from the First International Workshop on Long Wave Runup, J. Fluid Mech., 229, 675-688.
Mansinha, L. and Smylie, D. E., 1971, The Displacement Field of Inclined Faults, Bull. seism. Soc. Am., 61, 1433–1440.
Masson, F., Anvari, M., Djamour, Y., Walpersdorf, A., Tavakoli, F., Daignieres, M., Nankali, H. and Van Gorp, S., 2007, Large-scale velocity field and strain tensor in Iran inferred from GPS measurements; new insight for the present-day deformation pattern within NE Iran, Geophys. J. Int., 170, 436–440,.
McCall, G. J. H, 2002, A summary of the geology of the Iranian Makran, in: Clift P. D., Kroon D., Craig J. (Eds.), The tectonic and climatic evolution of the Arabian Sea Region, Geol. Soc. Lond. Spec. Publ., 195, 147–204.
Mirzaei, N., Gao, M. and Chen, Y. T., 1998, Seismic source regionalization for seismic zoning of Iran: major seismotectonic provinces, J. Earthquake Prediction Research, 7, 465-495.
Mokthari, M., Fard, I. A. and Hessami, K., 2008, Structural elements of the Makran region, Oman Sea and their potential relevance to tsunamigenesis, Nat. Hazards, 47, 185-199.
Musson, R. M. W., 2009, Subduction in the western Makran: The historian’s contribution, Geol. Soc. Lond., 166, 387–391.
Neetu, S., Suresh, I., Shankar, R., Nagarajan, B., Sharma, R., Shenoi, S. S. C., Unnikrishnan, A. S. and Sundar, D., 2011, Trapped waves of the 27 November 1945 Makran tsunami: Observations and numerical modeling, Nat. Hazards, 59, 1609-1618.
Okada, Y., 1985, Surface deformatipon due to shear and tensile faults in a half-space, Bull. seism. Soc. Am., 75, 1135-1154.
Okal, E. A. and Synolakis, C. E., 2008, Far-field tsunami hazard from mega-thrust earthquakes in the Indian Ocean, Geophys. J. Int., 172, 995-1015.
Oldham, R. D., 1893, A manual of the geology of India: stratigraphical and structural geology, 2nd ed, Geological Survey of India.
Page, W. D., Alt, J. N., Cluff, L. S. and Plafker, G., 1979, Evidence for recurrence of large-magnitude earthquakes along the Makran coast of Iran and Pakistan, Tectonophysics, 52, 533-547.
Quittmeyer, R. C. and Jacob, K. H., 1979, Historical and modern seismicity of Pakistan, Afghanistan, northwestern India, and southeastern Iran, Bull. seism. Soc. Am., 69, 773–823.
Rajendran, C. P., Rajendran, K., Hosseini, M. S., Beni, A. N., Nautiyal, C. M. and Andrews, R., 2012, The hazard potential of the western segment of the Makran subduction zone, northern Arabian Sea, Nat Hazards, 65, 219-238.
Satake, K. and Tanioka, Y., 1999, Source of Tsunami and Tsunamigenic earthquakes in subduction zones, Pure Appl. Geophys., 154, 467-483.
Schlȕter, H. U., Prexl, A., Gaedicke, Ch., Roese, H., Reichert, Ch., Meyer, H. and Daniels, C., 2002, The Makran accretionary wedge: sediment thickness and ages and the origin of mud volcanoes, Mar Geol, 185, 219–232.
Şengör, A. M. C., Altiner, D., Cin, A. and Ustaomer, T., 1988, Origin and assembly of the Tethyside orogenic collage at the expens of Gondwana Land, in: Audley Charles M. G., Flallam A. (Eds.), Gondwana and Tethys, Geol. Soc. Lond. Spec. Publ., 37, 119–181.
Shad Manaman, N., Shomali, H. and Koyi, H., 2011, New constraints on upper-mantle S-velocity structure and crustal thickness of the Iranian plateau using partitioned waveform inversion, Geophys. J. Int., 184,  247-267.
Smith, G. L., McNeill, L. C., Henstock, T. J. and Bull, J., 2012, The structure and fault activity of the Makran accretionary prism, J. Geophys. Res., 117, B07407.
Smith, G. L., McNeill, L. C., Wang, K., He, J. and Henstock, T. J., 2013, Thermal structure and megathrust seismogenic potential of the Makran subduction zone, J. Geophys. Res., 40, 8, 1528-1533.
Steketee, J. A., 1958, On Volterra's dislocation in a semi-infinite elastic medium. Can. J. Phys., 136, 192-205.
Stocklin, J., 1974, Northern Iran: Alborz mountains, Geol. Soc. Lond. Spec. Publ., 4, 212-237.
Vernant, Ph., Nilforoushhan, F., Hatzfeld, D., Abbassi, M. R., Vigny, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, A., Bayer, R., Tavakoli, F. and Chery, J., 2004 Present-day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and Northern Oman, Geophys. J. Int., 157, 381–398.
Vita-Finzi, C., 2002, Neotectonics on Arabian Sea coasts, in: Clift P. D., Kroon D., Craig J. (Eds.), The tectonic and climatic evolution of the Arabian Sea Region, Geol. Soc. Lond. Spec. Publ., 195, 87–96.
Zarifi, Z., 2006, Unusual subduction zones: case studies in Colombia and Iran, PhD thesis. University of Bergen, Norway.