Arabian Journal of Geosciences

, Volume 8, Issue 7, pp 4291–4298 | Cite as

The role of splay faulting in increasing the devastation effect of tsunami hazard in Makran, Oman Sea

  • Mohammad MokhtariEmail author
SI: 8th Gulf Seismic Forum (GSF)


There are both far- and near-field tsunamis that need to be considered for the Oman Sea region, and in addition, the landslide as a minor source requires special attention. The Makran subduction zone originated in the Cretaceous as part of the closing Tethyan seaways. It bent and broke oceanic sediments into an accretionary wedge that extends nearly 400 km northward from the present deformation front. The historical records indicate one unambiguous Makran tsunami in the east. It was generated in 1945 in the eastern part of the subduction zone. As for the tsunami, it reportedly reached heights of 12–15 m in Pasni, just north of the earthquake’s epicenter. There and in Karachi, its largest waves came ashore late enough, so it was suggested to be associated with landslides. But an alternative explanation that is the objective of this paper is the splay faults that exist in the Makran accretionary margin may have caused this late arrival and increase the run-up height observed in the near-field region after the initial tsunami. Several case studies indicated that splay faults are associated with subduction zones in the world. They develop within the sedimentary sequences as sediments are being added from the upper plate. The superimposed effect of splay faulting on tsunami wave heights in the near-field has also been observed in many mega-tsunami events. Thus, as mentioned above, to achieve this, first, we must identify and map the splay faults in the region, so, 2D seismic reflection data, which belongs to the National Iranian Oil Company, gathered in the Oman Sea in 2000 has been utilized. The result of this interpretation has been presented in map showing the major splay and normal faults, in the south and north, respectively. It is strongly suggested that the result of this study is to be utilized in future comprehensive tsunami hazard assessments in the region.


Makran Splay faults Seismic data Tsunami hazards Run-up heights Seafloor deformation 


  1. Aldama-Bustos G, Bommer JJ, Fenton CH, et al. (2009) Probabilistic seismic hazard analysis for rock sites in the cities of Abu Dhabi, Dubai and Ra's Al Khaymah, United Arab Emirates, GEORISK, Vol:3, ISSN:1749–9518, Pages:1–29Google Scholar
  2. Ambraseys NN, Melville CP (1982) A history of Persian earthquakes. Cambridge University Press, Cambridge, Britain, p 218Google Scholar
  3. Baba T, Cummins PR, Hori T, Kaneda Y (2006) High precision slip distribution of the 1944 Tonankai earthquake inferred from tsunami waveforms: possible slip on a splay fault. Tectonophysics 426:119–134CrossRefGoogle Scholar
  4. Byrne DE, Sykes LR, Davis DM (1992) Great thrust earthquakes and aseismic slip along the plate boundary of the Makran subduction zone. J Geophys Res 97(B1):449–478CrossRefGoogle Scholar
  5. Carayannis GP (2006) The potential of tsunami generation along the Makran subduction zone in the northern Arabian Sea, case study: the earthquake and tsunami of November 28, 1945. Science of Tsunami Hazard 24:358–384Google Scholar
  6. Deif A, El-Hussain I (2012) Seismic moment rate and earthquake mean recurrence interval in the major tectonic boundaries around Oman. J Geophys Eng 9(2012):773–783CrossRefGoogle Scholar
  7. Farhoudi G, Karig DE (1977) Makran of Iran and Pakistan as an active arc system. Geology 5:664–668CrossRefGoogle Scholar
  8. Fitch TJ, Scholz CH (1971) Mechanism of underthrusting in southwest Japan a model of convergent plate interactions. I Geophys Res 76:7260–7292CrossRefGoogle Scholar
  9. Fowler SR, White RS, Louden KE (1985) Sediment dewatering in the Makran accretionary prism, Earth Planet. Sci Lett 75:427–438Google Scholar
  10. Fukao Y (1979) Tsunami earthquakes and subduction processes near deep-sea trenches. J Geophys Res 84:2303–2314CrossRefGoogle Scholar
  11. Gaedicke C, Schlüter HU, Roeser H, Meyer H and Prexl A (2000) Seismic imaging and dynamic evolution of the Indian Plate boundary off Pakistan—9th Symposium on Dee Seismic Profiling of the Continents and their Margins—Ulvik, Norway, June 18–23.Google Scholar
  12. Marone C, Scholz CH (1988) The depth of seismic faulting and the upper transition from stable to unstable slip regimes. Geophys Res Letr I 5:621–624CrossRefGoogle Scholar
  13. Mokhtari M (2011) Tsunami in Makran Region and its effect on the Persian Gulf, in: edited by Mokhtari M, Tsunami—a growing disaster, InTech Publication, Open book publication:
  14. Mokhtari M, Abdollahie I, Hessami K (2008) Structural elements of the Makran region, Oman Sea and their potential relevance to tsunamigenisis. Nat Hazards 47:185–199CrossRefGoogle Scholar
  15. Page WD, Alt JN, Cluff LS, Plafker G (1979) Evidence for the recurrence of large magnitude earthquakes along the Makran coast of Iran and Pakistan. Tectonophysics 52:533–547CrossRefGoogle Scholar
  16. Park JO, Tsuru T, Kodaira S, Cummins PR, Kaneda Y (2002) Splay fault branching along the Nankai subduction zone. Science 297:1157–1160CrossRefGoogle Scholar
  17. Platt JP, Leggett JK, Young J, Raza H, Alam S (1985) Large scale sediment underplating in the Makran accretionary prism, southwest Pakistan. Geology 13:507–511CrossRefGoogle Scholar
  18. Quittmeyer RC, Jacob KH (1979) Historical and modem seismicity of Pakistan, Afghanistan, northwestern India, and southeastern Iran. Bull Seismol Soc Am 69(3):773–823Google Scholar
  19. Ravangard I, Mokhatri M and Hessami KH (2013) Identification of splay faults in the Makran region using seismic reflection data, submitted for publication to Earth Sciences Journal.Google Scholar
  20. Ryan HF, Scholl DW (1989) The evolution of forearc structures along an oblique convergent margin, central Aleutian Arc. Tectonics 8:497–516CrossRefGoogle Scholar
  21. Smith G et al (2013) The structure and fault activity of the Makran accretionary prism. J Geophys Res 117, B07407Google Scholar
  22. Strasser M, Moore GF, Kimura G, Yujin Kitamura G, Kopf AJ, Lallemant S, Oh Park J, Screaton EJ, Su X, Underwood MB, Zhao X (2009) Origin and evolution of a splay fault in the Nankai accretionary wedge. Nat Geosci 2:648–652CrossRefGoogle Scholar
  23. Sykes LR, Menke W (2006) Repeat times of large earthquakes: implications for earthquake mechanics. Bull Seismol Soc Am 96(5):1569–1596CrossRefGoogle Scholar
  24. White RS (1982) Deformation of the Makran accretionary sediment prism in the Gulf of Oman (north-west Indian Ocean), In: Leggett, J.K., (Ed.), Trench and Fore-Arc Geology: Sedimentation and Tectonics on Modern and Ancient Active Plate Margins, pp. 357–372.Google Scholar
  25. Youngs RR, Coppersmith KJ (1985) Implications of Fault Slip Rates and Earthquake Recurrence Models to Probabilistic Seismic Hazard Estimates. Bull Seism Soc Am 75(4):939–964Google Scholar
  26. Zarifi Z (2006) Unusual subduction zones: case studies in Colombia and Iran, Unpublished PhD thesis, the University of Bergen, Norway.Google Scholar

Copyright information

© Saudi Society for Geosciences 2014

Authors and Affiliations

  1. 1.International Institute of Earthquake Engineering and Seismology (IIEES)TehranIran

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