Articles | Volume 4, issue 4
Nat. Hazards Earth Syst. Sci., 4, 535–539, 2004

Special issue: Precursory phenomena, seismic hazard evaluation and seismo-tectonic...

Nat. Hazards Earth Syst. Sci., 4, 535–539, 2004

  27 Sep 2004

27 Sep 2004

Disturbances in groundwater chemical parameters related to seismic and volcanic activity in Kamchatka (Russia)

P. F. Biagi1,2, L. Castellana1, R. Piccolo1,2, A. Minafra1,2, G. Maggipinto1, A. Ermini3, V. Capozzi4,2, G. Perna4, Y. M. Khatkevic5, and E. I. Gordeev5 P. F. Biagi et al.
  • 1Department of Physics, University of Bari, Via Amendola, 173, 70126 Bari, Italy
  • 2INFM-Unity of Bari, Bari, Italy
  • 3Department of Engineering of Enterprise, University of Roma Tor Vergata, Via di Tor Vergata, 00133 Rome, Italy
  • 4Department of Biomedical Sciences, University of Foggia, Via L. Pinto, 71100 Foggia, Italy
  • 5Experimental and Methodical Seismological Department, Geophysical Service Russian Academy of Science, Pijp Av. 9, Petropavlovsk-Kamchatsky 683006, Russia

Abstract. Starting from 1992 geochemical data are being collected with a mean sampling frequency of three days in the form of the pH value and of the most common ions and gases in the groundwater in one deep well located in Petropavlovsk, the capital city of Kamchatka (Russia). On 1 January 1996 a strong eruption started from the Karymsky volcano, that is located about 100km far from the well, in the north-northeastern direction. At the same time, a large earthquake (M=6.9) occurred in the Karymsky area. On 5 December 1997 a very large earthquake (M=7.7) occurred offshore, at a distance of 350km from the well and towards the same direction. The analysis of the geochemical data shows clear variations in the raw temporal trends on both cases. For the first event, a clear premonitory phase appeared; for the second one, some pre-seismic variations could be revealed but permanent modifications of the chemistry of the water subsequent to the earthquake are very clear. In both cases the feature of the geochemical variations is consistent with an afflux of new water in the aquifer connected with the well and with an escape of the Carbon dioxide gas from the ground in different directions. A schematic model able to justify such a phenomenology and the connections of the geochemical variations with the previous tectonic activities is proposed.