Ground tilt variations in the Klyuchevskoi Volcano Area, Kamchatka

Abstract

We consider the results of ground tilt observations in the area of Klyuchevskoi Volcano, Kamchatka at the Klyuchi and Apakhonchich stations using photoelectric tiltmeters. An anomalous tilt was recorded during a period of increased activity in the summit crater of Klyuchevskoi Volcano in November 1979. In January and February 1980 three more cases of anomalous tilting before the volcano’s active periods were observed. The tilts exhibit some common kinematic features that are quite consistent with the activity periods. Various disturbing influences were estimated as affecting the observations of tilts related to seismic and volcanic events. For the first time in Kamchatka, the parameters of the five principal elastic-tide waves have been determined. Sea tides exerted an indirect effect on the amplitude factors γ(M2) on the E-W component at both sites to decrease them relative to the global value, γ(M2) = 0.7. We investigated the influence of sea tides on the elastic solid earth tide along the Trans-Kamchatka and Kola traverses. The observed and theoretical γ(M2) factors at both traverses situated in different geodynamic areas are in approximate agreement.