Increase of Order of Local Seismic Energy Release Caused by Water Level Variation in the Enguri High Dam Reservoir

It was reported earlier that water level periodic variation in a high dam reservoir may lead to the synchronizing influence on local seismic activity. Taking into account that phase synchronization is not related to strong functional relationships, in the present study small dynamical changes in seismic activity caused by water level variation were investigated. For this purpose the recurrence quantitative analysis (RQA) approach was used. Analysis was carried out on data sets of water level daily variation and released daily seismic energy. It was shown that when the external influence on the earth's crust caused by reservoir water becomes periodic the extent of the regularity of earthquake daily distribution essentially increases. (author)