An explosive eruption occurred at Bezymianny Volcano (Kamchatka Peninsula, Russia) on 24 December 2006 at 09:17 (UTC). Seismicity
increased three weeks prior to the large eruption, which produced a 12–15 km above sea level (ASL) ash column. We present field observations from 27 December 2006 and 2 March 2007, combined with satellite data collected from 8 October 2006 to 11 April 2007 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), as part of the instrument's rapid-response program to volcanic eruptions. Pixel-integrated brightness temperatures were calculated from both ASTER 90 m/pixel thermal infrared (TIR) data as well as 30 m/pixel shortwave infrared (SWIR) data. Four days prior to the eruption, the maximum TIR temperature was 45 °C above the average background temperature (−33 °C) at the dome, which we interpret was a precursory signal, and had dropped to 8 °C above background by 18 March 2007. On 20 December 2006, there was also a clear thermal signal in the SWIR data of 128 °C using ASTER Band 7 (2.26 μm). The maximum SWIR temperature was 181 °C on the lava dome on 4 January 2007, decreasing below the detection limit of the SWIR data by 11 April 2007. On 4 January 2007 a hot linear feature was observed at the dome in the SWIR data, which produced a maximum temperature of 700 °C for the hot fraction of the pixel using the dual band technique. This suggests that magmatic temperatures were present at the dome at this time, consistent with the emplacement of a new lava lobe following the eruption. The eruption also produced a large, 6.5 km long by up to 425 m wide pyroclastic flow (PF) deposit that was channelled into a valley to the south–southeast. The PF deposit cooled over the following three months but remained elevated above the average background temperature. A second field investigation in March 2007 revealed a still-warm PF deposit that contained fumaroles. It was also observed that the upper dome morphology had changed in the past year, with a new lava lobe having in-filled the crater that formed following the 9 May 2006 eruption. These data provide further information on effusive and explosive activity at Bezymianny using quantitative remote sensing data and reinforced by field observations to assist in pre-eruption detection as well as post-eruption monitoring.

A series of large caldera-forming eruptions (361–38 ka) transformed Gorely volcano, southern Kamchatka Peninsula, from a shield-type system dominated by fractional crystallization processes to a composite volcanic center, exhibiting geochemical evidence of magma mixing. Old Gorely, an early shield volcano (700–361 ka), was followed by Young Gorely eruptions. Calc-alkaline high magnesium basalt to rhyolite lavas have been erupted from Gorely volcano since the Pleistocene. Fractional crystallization dominated evolution of the Old Gorely magmas, whereas magma mixing is more prominent in the Young Gorely eruptive products. The role of rechargeevacuation processes in Gorely magma evolution is negligible (a closed magmatic system); however, crustal rock assimilation plays a significant role for the evolved magmas. Most Gorely magmas differentiate in a shallow magmatic system at pressures up to 300 MPa, ∼3 wt% H2O, and oxygen fugacity of ∼QFM + 1.5 log units. Magma temperatures of 1123–1218 °C were measured using aluminum distribution between olivine and spinel in Old and Young Gorely basalts. The crystallization sequence of major minerals for Old Gorely was as follows: olivine and spinel (Ol + Sp) for mafic compositions (more than 5 wt% of MgO); clinopyroxene and plagioclase crystallized at ∼5 wt% of MgO (Ol +Cpx + Plag) and magnetite at ∼3.5 wt% of MgO (Ol + Cpx + Plag +Mt). We show that the shallow magma chamber evolution of Old Gorely occurs under conditions of decompression and degassing. We find that the caldera-forming eruption(s) modified the magma plumbing geometry. This led to a change in the dominant magma evolution process from fractional crystallization to magma mixing. We further suggest that disruption of the magma chamber and accompanying change in differentiation process have the potential to transform a shield volcanic system to that of composite cone on a global scale.

In 2005, six major eruptions of four Kamchatka volcanoes (Bezymyannyi, Klyuchevskoy, Shiveluch, and Karymskii) occurred and the Avachinskii, Mutnovskii, and Gorelyi Kamchatka volcanoes and the Ebeko and Chikurachki volcanoes in northern Kurils were in a state of increased activity. Owing to a close collaboration between the KVERT project, Elizovo airport meteorological center, and volcanic ash advisory centers in Tokyo, Anchorage, and Washington (Tokyo, Anchorage, and Washington VAACs), all necessary measures for safe airplane flights near Kamchatka were taken and fatal accidents related to volcanic activity did not occur.

Представлены материалы исследований деятельности вулканов Карымского долгоживущего вулканического центра на Камчатке в 1996 г. Рассмотрены особенности динамики и вещественный состав пород одновременно начавшихся извержений вулкана Карымский и в кальдере Академии Наук. Эффузивно-эксплозивное извержение Карымского вулкана возобновилось после 14-летнего периода покоя и в течение года поставило через вершинный кратер -30 млн.т вещества андезитодацитового состава. Предполагается длительная эруптивная активность этого вулкана в ближайшие годы. Одновременно с типичной для Карымского вулкана активностью в 6 км южнее впервые на Камчатке в историческое время наблюдалось субаквальное эксплозивное извержение в озере, занимающем кальдеру Академии Наук. За 18ч извержения в северной части Карымского озера выросла постройка из пирокластического материала базальтового, андезитобазальтового состава с кратером диаметром 650 м. Объем извергнутого пирокластического материала оценивается в 0.04 км3, общий вес >70 млн.т. Обсуждены последствия извержений для окружающей среды, описаны оживление гидротермальной деятельности и образование новой группы горячих источников в кальдере Академии Наук, сделаны оценки прорывных паводков из Карымского озера и т.п.