Seismic Monitoring

The study aims to characterize the local seismicity close to the Enguri dam and identify the active fault segments in the area. One focus is to observe whether the local seismicity correlates with changes in the water level of the Jvari reservoir.

During Enguri High Dam construction times there had been a seismic network around Enguri (1972-1992) and first induced seismicity (Magnitude 4.7) occurred in 1979. However, in meantime the seismic network was significantly reduced and the next seismic station is at a distance of about 45 km to the dam.

Figure 1: Seismic network between 1972-1992 (A. Rietbrock, N. Karamzadeh, N. Tsereteli).

Figure 2: The seismicity recorded in the area before the start of DAMAST project (A. Rietbrock, N. Karamzadeh, N. Tsereteli, ESC presentation).

In the first years of DAMAST a new seismic network has been installed which includes even a station in Abkhazia where the Magnitude 4.7 event happened.

The event detection method includes the automatic (STA/LTA) detection in combination with visual inspection and template matching (Figure 4).

Figure 3:  Network which had been installed within DAMAST (A. Rietbrock, N. Karamzadeh, N. Tsereteli).

Figure 4 : Example for template matching for events recorded at station DOG.

In the time between October 2020 and August 2021 228 events have been detected and 122 of them could be localized. The magnitude range of closer events of the dam is between Ml = 0 and Ml = 1.8. The earthquake depths are rather shallow. The depth range where most events occur is between 3 and 6 km.

Figure 5: Number of recorded earthquakes from 2020 to 2021. This research is ongoing and will be updated soon.

Figure 6: Events recorded until August 2021.