Interaction between groundwater and earthquakes: seismic site characterization and coastal liquefaction potential in Cephalonia (Ionian Sea) from an updated dataset.

Citation:

Michalaki K, Kassaras I, Papathanassiou G, Koumantakis I, Vasileiou E, Markantonis K. Interaction between groundwater and earthquakes: seismic site characterization and coastal liquefaction potential in Cephalonia (Ionian Sea) from an updated dataset. 11th International Hydrogeological Congress of Greece [Internet]. 2017.

Abstract:

The subject of this work is the investigation of the interaction between groundwater and seismic waves, resulting in liquefaction of the soil, a particularly dangerous phenomenon. Therefore, estimates of liquefaction potential can significantly contribute to the prevention of such effects and consequently to reduction of the seismic risk. The study area is Cephalonia Island, the most earthquake prone region of Europe. A dataset consisting of seismic ambient noise, accelerograms and datasheet from geotechnical boreholes, obtained after the 2014 earthquake crisis, has been analysed using a series of methodologies. Ambient noise analysis provided amplification functions, Vs30 models and synthetic time histories for numerous sites across the 2014 epicentral area. These were used for the seismic site characterization across the western part of the island and the estimation of the liquefaction potential in the coastal areas of Argostoli and Lixouri, where liquefaction phenomena were observed after the occurrence of the two strongest earthquakes in 2014. The results of the analyses are found to be compliant with the overall arrangement of the 2014 secondary earthquake effects, implying for strong site effects and interaction with the groundwater.

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