EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Historical evidence warns about disastrous tele-tsunami risk on the coast of East Africa.

Vittorio Maselli1, Davide Oppo2, Andrew Moore3, Aditya Gusman4, Cassy Mtelela5, David Iacopini6, Elisante Mshiu5, Elinaza Mjema7, Marco Taviani8, and Joseph Ortiz9
Vittorio Maselli et al.
  • 1Department of Earth Sciences, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada (
  • 2School of Geosciences, University of Louisiana at Lafayette, Lafayette, Louisiana, United States
  • 3Department of Geology, Earlham College, Richmond, Indiana, United States
  • 4GNS Science, Lower Hutt, New Zealand
  • 5Department of Geology, University of Dar es Salaam, Dar es Salaam, Tanzania
  • 6Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Naples, Italy
  • 7Institute of Marine Sciences, ISMAR-CNR, Bologna, Italy
  • 8Department of Archaeology and Heritage, University of Dar es Salaam, Dar es Salaam, Tanzania
  • 9Department of Geology, Kent State University, Kent, Ohio, United States

The 2004 tsunami killed more than 200,000 people in Asia, but fewer than 300 in all East Africa. As a result, the search for ancient precursors has focused primarily along the coastlines of the Northern and Eastern Indian Ocean. No efforts to study past events were made in East Africa, leading to an underestimation of the tsunami risk in the region. Here we document a 1,000-yr old event that devastated a coastal Swahili settlement in Tanzania. Our study suggests a tsunami wave as the most likely explanation, in agreement with coeval tsunami deposits elsewhere across the Indian Ocean.  Numerical simulations of tsunami flooding suggest a megathrust earthquake from the Andaman-Sumatra subduction zone as a potential source, with a larger magnitude than the 2004 event. Our findings indicate that tele-tsunamis represent a serious threat to coastal societies along the Western Indian Ocean, with implications for future tsunami hazard and risk assessments.

How to cite: Maselli, V., Oppo, D., Moore, A., Gusman, A., Mtelela, C., Iacopini, D., Mshiu, E., Mjema, E., Taviani, M., and Ortiz, J.: Historical evidence warns about disastrous tele-tsunami risk on the coast of East Africa., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3354,, 2021.

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