LESVOS EVENT ANALYSIS NUMERICAL MODELLING PRESENTATION BY: GOZDE - - PowerPoint PPT Presentation

LESVOS EVENT ANALYSIS – NUMERICAL MODELLING

PRESENTATION BY: GOZDE GUNEY DOĞAN, METU, TURKEY

• A. ANNUNZIATO, G. Α. PAPADOPOULOS, A. YALCINER, O.NECMIOGLU, C. OZER

SOZDINLER, A. AGALOS, M. CHARALAMPAKIS, G. G. DOGAN, M. KLEANTHI, T. NOVIKOVA, P. PROBST, C. PROIETTI, I. TRIANTAFYLLOU

INTRODUCTION

• On 12 June 2017 at 12:28 UTC a strong earthquake of Moment Magnitude

Μw6.3 occurred in between Lesvos and Karaada islands.

• As well as Lesvos and Plomari, tsunami effected other islands nearby and on

the coasts of western Turkey.

• From

eyewitness accounts, video records and photos, we have

• bservations on Karaburun and Foca regions in Turkey.
• The tide-gauge on Bozcaada Island, located more than 100 km from the

epicentre, detected the arrival of the waves about 1 h after the event showing sea level change of a few cm.

• As METU, we conducted several numerical modelling works.

Bozcaada Karaburu n Foca

OBSERVATIO N POINTS

Bozcaada

Bozcaada Karaburu n Foca

OBSERVATIO N POINTS

Karaburun Yeniliman

Bozcaada Karaburu n Foca

OBSERVATIO N POINTS

Foca

VISUAL OBSERVATIONS KARABURUN

40 min after the earthquake

VISUAL OBSERVATIONS FOCA

VISUAL OBSERVATIONS FOCA

NUMERICAL MODELING BY METU NAMI DANCE

• Tsunami Numerical Model NAMI DANCE in GPU Environment
• NAMI DANCE: Solves Nonlinear Shallow Water Equations (NLSWE) with a

bottom friction term using the Leap-Frog numerical scheme

• The 1km x 1km Finite Fault Model proposed by NOA is used as the tsunami

source in the calculations.

Input tsunami source Defined Rupture Pre-determined wave form Time history of water surface fluctuations Propagatio n Coastal amplification Inundation

NAMI DANCE

NUMERICAL MODELING BY METU NAMI DANCE

NUMERICAL MODELING BY METU

STUDY DOMAIN, TSUNAMI SOURCE AND OBSERVATION POINTS

NUMERICAL MODELING BY METU

COORDINATES AND WATER DEPTHS AT OBSERVATION POINTS

Observation Point Longitude (degree) Latitude (degree) Water depth in bathymetry file (m) Plomari harbor 26.3700474E 38.9730774N 1.95 Karaburun Yeniliman 26.4372631E 38.6711561N 1.56 Foca 26.7405112E 38.6650331N 1.71

Distribution of Maximum Water Elevations Computed by 60min Simulations

Distribution of Maximum Current Velocities Computed by 60min Simulations

NUMERICAL MODELING RESULTS

Current (m/s) Time History of Water Elevations at Plomari Harbor Time History of Current Velocities at Plomari Harbor

NUMERICAL MODELING RESULTS

Time History of Water Elevations at Karaburun Yeniliman Time History of Current Velocities at Karaburun Yeniliman Current (m/s)

NUMERICAL MODELING RESULTS

Time History of Water Elevations at Foca Time History of Current Velocities at Foca Current (m/s)

NUMERICAL MODELING RESULTS

Bozcaada Time History of Water Elevations at Bozcaada Time History of Current Velocities at Bozcaada

COMPARISONS AND DISCUSSIONS

COMPARISONS AND DISCUSSIONS

COMPARISONS AND DISCUSSIONS

DISCUSSIONS

• There are some critical points (Candarli, Aliaga, Bademli and Dikili ) where

water level elevations increase more than other locations. The observation points (Foca, Karaburun Yeniliman and Plomari Harbor) are among those locations.

• There are some deviations of the numerical results from the observations

which may be caused by internal errors of the numerical modelling process, the errors in estimation of the tsunami source or due to the bathymetry data.

• In small events, like this Lesvos event, the numerical modelling process

requires more precise work and the deviations

• f

the numerical estimations may be higher.

• It can be said that, for this case, the numerical models are quite able to

estimate the arrival time or the wave periods and the different models are mostly in agreement in the trend of the waves.

THANK YOU!