More than 65 potentially active volcanoes on the Kamchatka Peninsula and the Kurile Islands pose a substantial threat to aircraft on the Northern Pacific (NOPAC), Russian Trans-East (RTE), and Pacific Organized Track System (PACOTS) air routes. The Kamchatka Volcanic Eruption Response Team (KVERT) monitors and reports on volcanic hazards to aviation for Kamchatka and the north Kuriles. KVERT scientists utilize real-time seismic data, daily satellite views of the region, real-time video, and pilot and field reports of activity to track and alert the aviation industry of hazardous activity. Most Kurile Island volcanoes are monitored by the Sakhalin Volcanic Eruption Response Team (SVERT) based in Yuzhno-Sakhalinsk. SVERT uses daily moderate resolution imaging spectroradiometer (MODIS) satellite images to look for volcanic activity along this 1,250-km chain of islands. Neither operation is staffed 24 h per day. In addition, the vast majority of Russian volcanoes are not monitored seismically in real-time. Other challenges include multiple time-zones and language differences that hamper communication among volcanologists and meteorologists in the US, Japan, and Russia who share the responsibility to issue official warnings. Rapid, consistent verification of explosive eruptions and determination of cloud heights remain significant technical challenges. Despite these difficulties, in more than a decade of frequent eruptive activity in Kamchatka and the northern Kuriles, no damaging encounters with volcanic ash from Russian eruptions have been recorded.

The active andesitic Zhupanovsky Volcano consists of four coalesced stratovolcano cones. The historical explosive eruptions of 1940, 1957, and 2014‒2016 discharged material from the Priemysh Cone. The recent Zhupanovsky eruptions were studied using satellite data supplied by the Monitoring of Active Volcanoes in Kamchatka and on the Kuril Islands information system (VolSatView), as well as based on video and visual observations of the volcano. The first eruption started on October 22 and lasted until October 24, 2013. Fumaroles situated on the Priemysh western slope were the centers that discharged gas plumes charged with some amount of ash. The next eruption started on June 6, 2014 and lasted until November 20, 2016. The explosive activity of Zhupanovsky was not uniform in 2014–2016, with the ash plumes being detected on satellite images for an approximate total duration of 112 days spread over 17 months. The most vigorous activity was observed between June and October, and in November 2014, with a bright thermal anomaly being nearly constantly seen on satellite images around Priemysh between January and April 2015 and in January–February 2016. The 2014–2016 eruption culminated in explosive events and collapse of parts of the Priemysh Cone on July 12 and 14, November 30, 2015, and on February 12 and November 20, 2016.

Ash clouds resulting from explosive volcanic eruptions pose a real threat to human (for aircraft flights, airports operations, etc.); therefore, the detection, monitoring, and forecast of their movement is an urgent and important issue. The features and examples of application of the new tool developed on the basis of "Monitoring of active volcanoes of Kamchatka and the Kurile Islands" information system (VolSatView) are described. It allows the integrated monitoring and forecasting of ash cloud transport using the data of remote sensing and mathematical modeling as well as the assessment of the parameters of explosive events.

On Kamchatka, detailed geologic and geomorphologic mapping of young volcanic terrains and observations on historical eruptions reveal that landslides of various scales, from small (0.001 km3) to catastrophic (up to 20–30 km3), are widespread. Moreover, these processes are among the most effective and most rapid geomorphic agents. Of 30 recently active Kamchatka volcanoes, at least 18 have experienced sector collapses, some of them repetitively. The largest sector collapses identified so far on Kamchatka volcanoes, with volumes of 20–30 km3 of resulting debris-avalanche deposits, occurred at Shiveluch and Avachinsky volcanoes in the Late Pleistocene. During the last 10,000 yr the most voluminous sector collapses have occurred on extinct Kamen' (4–6 km3) and active Kambalny (5–10 km3) volcanoes. The largest number of repetitive debris avalanches (> 10 during just the Holocene) has occurred at Shiveluch volcano. Landslides from the volcanoes cut by ring-faults of the large collapse calderas were ubiquitous. Large failures have happened on both mafic and silicic volcanoes, mostly related to volcanic activity. Orientation of collapse craters is controlled by local tectonic stress fields rather than regional fault systems.

Specific features of some debris avalanche deposits are toreva blocks — huge almost intact fragments of volcanic edifices involved in the failure; some have been erroneously mapped as individual volcanoes. One of the largest toreva blocks is Mt. Monastyr' — a ∼ 2 km3 piece of Avachinsky Somma involved in a major sector collapse 30–40 ka BP.

Long-term forecast of sector collapses on Kliuchevskoi, Koriaksky, Young Cone of Avachinsky and some other volcanoes highlights the importance of closer studies of their structure and stability.

We determine a 3-D P-wave velocity structure of the mantle down to 700 km depth under the Kamchatka peninsula using 678 P-wave arrival times collected from digital seismograms of 75 teleseismic events recorded by 15 portable seismic stations and 1 permanent station in Kamchatka. The subducting Pacific slab is imaged clearly that is visible in the upper mantle and extends below the 660-km discontinuity under southern Kamchatka, while it shortens toward the north and terminates near the Aleutian–Kamchatka junction. Low-velocity anomalies are visible beneath northern Kamchatka and under the junction, which are interpreted as asthenospheric flow. A gap model without remnant slab fragment is proposed to interpret the main feature of high-V anomalies. Combining our tomographic results with other geological and geophysical evidences, we consider that the slab loss may be induced by the friction with surrounding asthenosphere as the Pacific plate rotated clockwise at about 30 Ma ago, and then it was enlarged by the slab-edge pinch-off by the asthenospheric flow and the presence of Meiji seamounts. As a result, the slab loss and the subducted Meiji seamounts have jointly caused the Pacific plate to subduct under Kamchatka with a lower dip angle near the junction, which made the Sheveluch and Klyuchevskoy volcanoes shift westward.

Kizimen Volcano began to erupt in December 2010. The eruption was preceded by a precursory period of seismicity that lasted for 20 months. This paper discusses the space-time features of the precursory seismicity. We provide a brief description of this explosive and effusive eruption between December 2010 and March 2013. The eruption started with some explosive activity followed by extrusion of a viscous lava flow. The extrusion of viscous andesitic magma and the motion of the lava flow down the slope were accompanied by unusual seismicity in the form of the quasiperiodic occurrence of microearthquakes, the so-called drumbeat phenomenon. It is shown that the occurrence of a drumbeat was first recorded during the extrusion process at the volcano's summit. Subsequently, the drumbeat mode of activity was caused by the front of the viscous lava flow as it was moving down the slope. The dynamic parameters of the microearthquakes varied in accordance with the dimensions of the lava flow front. The motion of the main tongue of the lava flow (March to September 2011) gave rise to drumbeat I with energy classes of microearthquakes K = 3-5.5, while the second tongue, which was smaller than the first, produced drumbeat II with microearthquakes of K < 3 during its motion down the slope. In January 2013 we saw a phenomenon similar to the drumbeat that was recorded at the start of the eruption. This was caused by an obelisk being extruded at the volcano's summit. В© 2014 Pleiades Publishing, Ltd.