The chronology, dynamics, and parameters of seven large eruptions of Avacha Volcano were reconstructed for its IAv andesitic period 7250-370014C years B.P., which began after a >2000-year period of relative quiescence. Their juvenile (andesitic pyroclastics) and resurgent products are described, and the geological and geomorphological consequences are evaluated. The largest eruption occurred 715014C years B.P. (8-10 km3 of erupted material). The subsequent events occurred 5700 (≥0.34 km3), 5600 (≥0.4 km3), 5500 (>1.34 km3), 5000 (≥0.5 km3), 4500 (>1.1 km3), and 4000 (≥0.6 km3) 14C years B.P. The erupted rocks were dominated by tephra; pyroclastic flows occurred only during the events of 5500 and 5000 years ago. It is believed that most of the eruptions produced acid peaks of varying intensity in the Greenland ice sheet.

This paper presents the results of studying the spatial distribution and structural setting of magnesian basalts and andesites in the Northern group of Kamchatkan volcanoes and in the junction zone of the Kuril-Kamchatka and Aleutian island arcs. The morphology and geologic structure of unique Kamchatkan magnesian basalt stratovolcanoes are described: Kharchinsky, Zarechnyi, and the Kharchinsky regional zone of cinder cones. The reported evidence includes the ages and eruptive histories, and productivities of the volcanoes and the volumes and weights of their edifices. The magnesian basalts were erupted 40-50 thousand years ago, for the first time during the Holocene.

Results of complex study of pyroclastic deposits from Bezymianny and Schiveluch volcanoes are present in this work. Comparative characteristics of engineering-geological features are given for various genetic types of pyroclastic deposits from andesitic volcanoes, as well as for pyroclastic deposits from andesitic and basaltic volcanoes on the whole.
Criteria for distinguishing genetic types of pyroclastic deposits from andesitic volcanoes have been substantiated.

This study revealed that the giant cirque of Bakening Volcano had been produced by its eruption ca. 8000-8500 carbon-14 year ago. The eruption is supposed to have been heralded by a large earthquake (M > 7) resulting in the collapse and slide of the SE sector of the cone. The landslide unroofed the hydrothermal system and triggered an explosion which was followed by an ash-and-block pyroclastic flow. A rockslide avalanche rolled down into the valley of the Srednyaya Avacha River and travelled as far as 10-11 km along it. The avalanche deposited its debris material over an area of 18-20 km2 measuring 0.4-0.5 km3 in volume. These deposits dammed the river, produced two lakes (Bezymyannoe and Verkhneavacha), and gave birth to a large lahar which traveled along the valley much farther.