The landslide source of the eastern Mediterranean tsunami on 6 February 2023 following the Mw 7.8 Kahramanmaraş (Türkiye) inland earthquake

Mohammad Heidarzadeh, Aditya Riadi Gusman, Iyan Eka Mulia

Research output: Contribution to journalArticlepeer-review

4 Citations (SciVal)

Abstract

This paper presents the first example of how to systematically identify the submarine landslide source of a tsunami using an innovative hybrid approach. This ground-breaking method is developed to resolve the puzzle around the source mechanism of the mysterious tsunami observed on 6th February 2023 in the Eastern Mediterranean Sea. The tsunami followed the two inland M w 7.8 and M w 7.5 Türkiye–Syria earthquakes, which occurred consequently with a 9 h interval on this day. The first earthquake (M w 7.8) had an epicentral distance of 90 km from the nearest coast, which is closer than the second one (M w 7.5) to the coast and yet its crustal deformation was almost entirely limited to inland. Therefore, the co-seismic surface displacement generated by the earthquake was ruled out as the source of the tsunami, confirmed by numerical modelling. Here, we hypothesized that the tsunami was most likely generated by a submarine landslide triggered by the earthquake. Analysis of tide gauge observations revealed that the waves arrived from 27 min to 48 min after the first earthquake (M w 7.8) at different coastal locations, implying that the potential submarine landslide was triggered by the first earthquake (M w 7.8). Backward tsunami travel time mapping using tide gauge observations guided us to constrain the area of the potential landslide. We approximated the dimensions of the landslide using spectral analysis of the tsunami observations. Consequently, an iterative trial-and-error approach was employed to confirm the landslide source of the tsunami by defining various informed alternative landslide scenarios and applying numerical modeling. Modelling showed that a submarine landslide can reproduce the tsunami observations reasonably well. It is located on a steep slope of the seafloor approximately 50 km from Arsuz. The submarine landslide is estimated to have caused a seafloor deformation measuring approximately 16 km in length and 4.0 km in width.

Original languageEnglish
Article number50
Number of pages16
JournalGeoscience Letters
Volume10
Issue number1
Early online date20 Oct 2023
DOIs
Publication statusPublished - 1 Dec 2023

Bibliographical note

Funding Information:
Some figures were drafted using the GMT mapping tool (Wessel and Smith 1998). We acknowledge the University of Bath Institutional Open Access Fund. A. R. Gusman was supported by the New Zealand Ministry for Business, Innovation, and Employment (MBIE) through the Strategic Science Investment Fund (SSIF) and the Rapid Characterization of Earthquakes and Tsunami: Fewer deaths and faster recovery project (Endeavour fund). We are grateful to Prof Kenji Satake (Editor-in-Chief) and Dr Anawat Suppasri (Editor) for their helpful comments. The manuscript benefited from constructive review comments from two anonymous reviewers for which we are grateful.

Funding Information:
This study is supported by the Great Britain Sasakawa Foundation grant no. 6217 (awarded in 2023). We acknowledge the University of Bath Institutional Open Access Fund.

Publisher Copyright:
© 2023, Asia Oceania Geosciences Society (AOGS).

Keywords

  • Kahramanmaraş earthquake
  • Landslide
  • Mediterranean Sea
  • Numerical modelling
  • Tsunami
  • Türkiye

ASJC Scopus subject areas

  • General Earth and Planetary Sciences

Fingerprint

Dive into the research topics of 'The landslide source of the eastern Mediterranean tsunami on 6 February 2023 following the Mw 7.8 Kahramanmaraş (Türkiye) inland earthquake'. Together they form a unique fingerprint.

Cite this