The East Aegean See strong earthquake(Mw6.3) of 12 June 2017 and its associated tsunami: a detailed study

Info

Category
EARLY WARNING - POST EVENT STUDY
Owner
flag Turkey Bogaziçi University Kandilli Observatory and Earthquake Research Institute (Turkey)
Activation Date
22-09-2017
Conclusion Date
15-03-2018
Experts
  • Dr. G.A. Papadopoulos (NOA) (Greece)
  • Dr. Ceren Özer Sözdinler (KOERI) (Turkey)

 

Purpose,Objectives and Scope

The objective of the proposal is to perform a joint Greek-Turkish post-event study of the strong earthquake (Mw6.3) that ruptured offshore south Lesvos Isl. (Greece) on 12 June 2017 as well as of the small tsunami in Turkish and Greek coasts that associated the earthquake. This event is the first that happened in that area in the modern instrumental period of seismicity. Therefore, valuable instrumental data are available to better understand the seismotectonics of the area and the field of ground motion produced by the earthquake. In addition, since the earthquake caused damage mainly in south Lesvos but also in other areas (e.g. Chios Isl., Greece; several localities in W. Turkey) macroseismic data sets are very useful to assess the level of damage and to interpret the damage geographical distribution. The small tsunami triggered by the earthquake was recorded from several sea level stations in Greece and Turkey, shot in videos and observed by eyewitnesses, reminded the tsunami hazard existing not only in the area but in the Mediterranean Sea in general. Therefore, the study will also include analysis of the tsunami observations and comparison with the results of tsunami numerical modeling both with moderate and fine-gridded bathymetric/topographic data aiming to test the validity of the earthquake and tsunami models. Finally, the improvement of the tidegauge network in the area will be examined in the prospect of improving early warning capabilities.

Revealing the existence of tsunami-prone coastal regions in Aegean Sea, the outcomes of this proposal would remarkably contribute to emphasize the tsunami potential in Aegean Sea and would satisfy the needs of national authorities, both in Greece and Turkey and also in the neighboring countries in Mediterranean Sea, in order to increase public awareness and preparedness in the region against tsunami disaster.

The proposed study will incorporate three main parts.

- The first will focus in the past earthquake and tsunami history of the East Aegean Sea where the shock of 12 June 2017 occurred. The aim is to evaluate the level of knowledge so far about the earthquake phenomena that produce tsunamis in the area, the potential of tsunami generation and the mechanism s that drive tsunami generation.

- In the second part the intention is to study in details the strong earthquake (Mw6.3) of 12 June 2017, its aftershock sequence, the focal mechanism, the rupture process in the seismic source, the field of strong ground motion (ground accelerations, shake map), the building damage and the ground failures caused.

- Having collected all these types of knowledge, the third part of the study will focus in understanding the generation of the small tsunami from the particular seismic source. Tsunami observations will be compiled from official reports, eyewitness accounts, and video records. Tsunami simulation will follow based on a homogeneous seismic fault model (Okada elastic deformation) and a heterogeneous fault model represented by the rupture model expected to come out from the second part of the study. I t is intended to use bathymetry of high resolution in order to calculate sea level fluctuations at the tide gauges compatible with the recorded values. The validity of the models will be tested by comparing tsunami hydrodynamic parameters (e.g. wave amplitude, current velocity, flow depth, wave first motion polarity etc.). The third part of the study will also include suggestions for increasing the instrumental monitoring capabilities of tsunamis in the area.

 

Tasks and Deliverables

Task 1

Task 1 - Compilation and evaluation of past earthquakes and tsunami events in East Aegean Sea.
Deliverables Title Type Timing
D1.1 Past earthquakes and tsunami events in the East Aegean Sea Report

PDF

M1

Task 2

Task 2 - Study of the 12 June 2017 Aegean Sea earthquake (Mw6.3).
Deliverables Title Type Timing
D2.1 Seismic evaluation of the Mw6.3, 12 June 2017 East Aegean Sea earthquake Report

PDF

M2

Task 3

Task 3 – Determination of tsunami hydrodynamic parameters due to the Mw6.3 Aegean Sea earthquake of 12 June 2017 by tsunami simulations.
Deliverables Title Type Timing
D3.1 Simulation results of the tsunami generated by the Mw6.3, 12 June 2017 East Aegean Sea earthquake Report

PDF

M3-M4

Task 4

Task 4 – Conclusions - Recommendations for the Tsunami Risk Reduction in the MS and the Mediterranean Region.
Deliverables Title Type Timing
D4.1 Conclusions and recommendations for the Tsunami risk reduction in the MS and the Mediterranean Region. Final report

PDF

M4