Geodesic monitoring of ground deformations at Klyuchevskoy Volcano in 1978–2014, Kamchatka

Measured values are given - slant distances and elevations between geodetic marks on the northeast slope of Klyuchevskaya volcano for 1978–2014. As a rule, a rise was observed before the secondary and summit eruptions, and the end of the eruptions was accompanied by the lowering of the volcano slope. According to the longest series of observations of vertical displacements from 1979 to 2014. on the “Kirgurich” radial profile, the rise of the volcano slope is determined to increase as it approaches its crater. The maximum displacements occurred two years before the start of the “Predskazannuy” side breakthrough in 1983, and before the summit eruptions of 2003–2004 and 2007. At a distance of 27 km from the crater of the volcano, the vertical displacements become insignificant. It is shown that points located at altitudes from 2000 meters to 3000 meters are subject to deep creep, i.e. sliding down. The displacement rates of such points reached 5–20 cm/year. Significant horizontal displacements of geodetic points occurred near incidental breaks on March 6, 1980 and March 8, 1983. From 1989–1993. until 2014, reductions of all lengths of lines from 5 to 20 mm were observed, which indicated compression of the northeast slope of Klyuchevskaya volcano.