Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 10 7 2010 10.5194/nhess-10-1629-2010 http://www.nat-hazards-earth-syst-sci.net/10/1629/2010/ http://www.nat-hazards-earth-syst-sci.net/10/1629/2010/nhess-10-1629-2010.html http://www.nat-hazards-earth-syst-sci.net/10/1629/2010/nhess-10-1629-2010.pdf 1629 1633 2010-07-29 Connection of large earthquakes occurring moment with the movement of the Sun and the Moon and with the Earth crust tectonic stress character M. K. Kachakhidze manana k@hotmail.com R. Kiladze N. Kachakhidze V. Kukhianidze G. Ramishvili Department of Natural Sciences, St. Andrew The First-Called Georgian University of The Patriarchy of Georgia, Tbilisi, Georgia Department of Natural Sciences, Ilia State University, Abastumani Astrophysical Observatory, Tbilisi, Georgia It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. <br><br> Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. <br><br> The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. <br><br> In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region. Davidson, S.: Solar and Lunar Triggers on Earthquakes and Volcanic Eruptions, Gravity Concepts, Sec 70, 175–181, 2~March 2002. Davidson, S.: High Tides Trigger Earthquakes, Gravity Concepts, Sec 30, Rev 1, 2005. Harris, R. A.: Earthquake stress triggers, stress shadows, and seismic hazard, in: Special Section: Seismology, Current Science, 79(9), 1215–1225, 2000. Jackson, J.: Partitioning of Strike – Slip and Convergent Motion Between Eurasia and Arabia in Eastern Turkey and the Caucasus, J. Geophys. Res., 97(89), 12.471–12.473, 10~August 1992. Kachakhidze, M., Kachakhidze, N., Kiladze, R., Kukhianidze, V., and Ramishvili, G.: Tectonic sources of caucasus strong earthquakes, Nat. Hazards Earth Syst. Sci., 4, 53–58, doi:10.5194/nhess-4-53-2004, 2004. Kiladze, R., Kachakhidze, M., Kukhianidze, V., Kachakhidze, N., and Ramishvili, G.: Study of possible relationships between strong earthquakes and astronomical phenomena for seismoactive regions of the Caucasus, Turkey and Greece, Bulletin of Georgian Academy of Sciences, 155(N3), 367–369, 1997. Kiladze, R., Kachakhidze, M., Kukhianidze, V., Kachakhidze, N., and Ramishvili, G.: A Search of Possible Relations Between Large Earthquakes and Astronomic Phenomena: the Caucasian Seismic region, J. Vulkanol. Seismol., (N3), 75–80, 2005. Lopes, R. M. C., Malin, S. R., Mazzarella, A., and Palumbo, A.: Lunar and solar triggering of earthquakes, Phys. Earth. Planet. In., 59, 127–129, 1990. Nikolaev, A. V.: On the earthquake triggering by the Earth's tide and underground nuclear explosions, in: Earthquakes induced by underground nuclear explosions, NATO ASI Series, 2-Environment, 255–266, 1995. Nikolaev, A. V. and Nikolaev, V. A.: Lithosperic stress state in South Americans inferred from tidal triggering of erthquakes, Geophys. J. Int., 35(N3), 329–339, 1996. Rydelek, P. A., Sacks, I. S., and Scarpa, R.: On tidal triggering of earthquakes at Campi Flegrei, Italy, Geophys. J. Int., 109, 125–137, 1992. Tanaka, S., Sato, H., Matsumura, S., and Ohtake, M.: Tidal triggering of earthquakes in the subducting Philippine Sea plate beneath the locked zone of the plate interface in the Tokai region, Japan, Tectonophysics, 417, 69–80, 2006. Tanaka, S.: Tidal triggering of earthquakes precursory to the recent Sumatra megathrust earthquakes of 26 December 2004 ($M_w$9.0), 28 March 2005 ($M_w$8.6), and 12 September 2007($M_w$8.5), Geophys. Res. Lett., 37(2), L02301, doi:10.1029/2009GL041581, 2010. Tsuruoka, H., Ohtake, M., and Sato, H.: Statistical test of the tidal triggering of earthquakes: contribution of the ocean tide loading effect, Geophys. J. Int., 122, 183–194, 1995. van Ruymbeke, M., Zhu, P., Cadicheanu, N., and Naslin, S.: Very Weak Signals (VWS) detected by stacking method according to different astronomical periodicities (HiCum), Nat. Hazards Earth Syst. Sci., 7, 651–656, doi:10.5194/nhess-7-651-2007, 2007.