Monogenetic volcanic fields are frequently located in the faulted area and in clusters which are associated with the particular geometry of the magmatic chambers and structures of the magma plumbing system in the crust. The method of cluster analyses of the spatial distribution and morphometric characteristics of the cinder cones was used in our research of the conditions of origin and evolution of one of the largest monogenetic fields in Kamchat-ka back-arc-the Anaunsky Dol, or Anaun MVF. Kamchat-ka subduction system is located at the northwestern part of the Pacific at the convergent boundary of the Okhotsk and Pacific plates. Today, Sredinny Range represents its back-arc part and is characterized by the wide distribution of the monogenetic volcanic fields: it has more than 1000 cinder cones, which deposits cover the area of about 8500 km2 (Laverov, 2005; Ogorodov et al., 1972) (Fig. 1). Sredinny Range has a complex structure with several volcanic provinces with different geological history and variable composition of products. Anaun monogenetic volcanic field occupies one of the lowest sections of the whole Sredinny Range. The youngest volcanism in this area (according to the geological map, it was formed in Quaternary times, although our geochemical research and isotopic dating shows its earlier age) is confined to the lowered block of basement rocks. Shield volcanoes, volcanic ridges, cinder and lava cones are located on a low-laying volcanic dale. We made an attempt to make a spatial analysis of distribution of the volcanic edifices and to quantitatively estimate the structural control of the magma plumbing channels. Based on a digital relief model (DEM SRTM, spatial resolution 30 m) we distinguished more than 100 morphometrically expressed cinder cones. For them, using semi-automatic mode, we estimated the morphometric characteristics: height, diameter of the basement, height/basement ratio, angle of the slope, volume of the edifice. With time, cinder cones change their shape due to the erosion processes. Therefore, finally the edifice height is decreased while the basement diameter increased. Determination of the morphometric parameters allowed us to compose a relative age scale for the cinder cones located in Anaun monogenetic volcanic field. Spatial analysis has shown that cones tend to form series of clusters, which are associated with the systems of lineaments. Statistically significant patterns in the cinder cones distribution were then compared with the strike of lineaments to estimate possible location of the magma feeding channels.

Проведено сравнение палеовариаций магнитного поля Земли, полученных по параллельным разрезам голоценового почвенно-пирокластического чехла вулкана Малый Семячик на Камчатке. Показано, что в интервале возраста 300 — 6000 лет назад наблюдается подобие изменений направления остаточной намагниченности подтверждающее первичность этой намагниченности и пригодность ее для реконструкции истории геомагнитного поля. Палеовариации, выделенные для интервала 1000 — 4000 лет назад, прослежены в одновозрастных слоях в 240 км к северу, в разрезе тефры Ключевского вулкана.
Выяснено, что вследствие связанной со спецификой формирования отложений тефры возможности выпадения из разрезов отдельных горизонтов для получения достаточно детальной картины палеовариаций необходимо изучение двух или более параллельных разрезов.
Рис. 6, библ. 3 назв.

Since Bezymianny Volcano resumed its activity in 1956, eruptions have been frequent; recently with up to 1–2 explosive events per year. To investigate deformation related to this activity we installed a GPS network of 8 continuous and 6 campaign stations around Bezymianny. The two striking observations for 2005–2010 are (1) rapid and continuous network-wide subsidence between 8 and 12 mm/yr, which appears to affect KAMNET stations more than 40 km away where we observe 4–5 mm/yr of subsidence, and (2) only the summit station BZ09 shows slight deviations from the average motion in the north component at times of eruptions.
The network-wide subsidence cannot be explained by tectonic deformation related to the build-up of interseismic strain due to subduction of the Pacific plate. A first order model of surface loading by eruptive products of the Kluchevskoy Group of Volcanoes also explains only a fraction of the subsidence. However, a deep sill at about 30 km under Kluchevskoy that constantly discharges material fits our observations well. The sill is constrained by deep seismicity which suggests 9.5 km width, 12.7 km length, and a 13° dip-angle to the south-east. We infer a closing rate of 0.22 m/yr, which implies a volume loss of 0.027 km3/yr (0.16 m/yr and 0.019 km3/yr considering surface loading). Additional stations in the near and far field are required to uniquely resolve the spatial extent and likely partitioning of this source.
We explain the eruption related deformation at BZ09 with a very shallow reservoir, likely within Bezymianny's edifice at a depth between 0.25 km and 1.5 km with a volume change of 1–4 × 10− 4 km3. Much of the material erupted at Bezymianny may be sourced from deeper mid-crustal reservoirs with co-eruptive volume changes at or below the detection limit of the GPS network. Installation of more sensitive instruments such as tiltmeters would allow resolving of subtle co-eruptive motion.