Theories are presented about the time of origin, dynamics and formation mechanism of active volcanoes in the Kuril-Kamchatka zone during the Late Pleistocene-Holocene period. The study was based on more than 500 radiocarbon dates and the results of geological, geomorphological, tephrochronological and isotopic geochronological research. It is noted that there are different rhythms in the activity of the volcanoes and in the mechanisms and rates of formation of the volcanic structures. Periods of synchronous activity of the volcanoes on Kamchatka and the Kuril islands, and apparently, in other volcanic areas are identified, suggesting their global nature. The concept of "active volcano' is discussed. -P.Cooke

We discuss results of 14C dates obtained from areas of young volcanoes in Kamchatka. We apply these dates to reconstructing regional volcanic activity during the Holocene.

The eruptive history of Ebeko Volcano is described since its origin about 2400 years ago until the beginning of the 17th century. Six stages of increased activity each lasting 200-300 years were separated by repose periods of the same duration. The eruption of juvenile material (lava and pyroclastics) took place at the first stage only (420-200 B.C.). All eruptions that followed were phreatic events of varying vigor. It is shown that, except for the first eruptive stage, the main volcanic hazard for the Ebeko area and the town of Severo-Kurilsk near by comes from large lahars and tephra fallout. -from Journal summary

По историческим сведениям, дополненным тефрохронологическими исследованиями и материалами аэрофотосъемок I960, 1987, 1988, 1990 гг. района в. Эбеко, детально восстановлены последствия его извержений XVII-XX вв. Показано, что все извержения были фреатическими и условно фреатомагматическими с источником теплового питания в виде сильно нагретого дайково-силлового комплекса объемом более 1 км . приуроченного к зоне растяжения ССВ (аз. 25°) простирания, вдоль которого расположены вулканы хр. Вернадского на о-в Парамушир. Предполагается, что в будущем главная опасность для г. Северо-Курильска и прилежащих участков связана с прохождением большеобъемных лахаров по рекам Кузьминка и Матросская, начинающихся на в. Эбеко, в меньшей степени - с пеплопадами этого и других вулканов Северных Курил и Южной Камчатки. Доказывается, что серьезная угроза городу может возникнуть при будущем извержении в. Эбеко типа его извержения 1934-1935 гг. Рекомендованы меры для защиты города.

Previous data are summarized and new evidence is presented on the Avacha eruptions of 1926-1927, 1938, and 1945. The last eruption of January 1991 is described. The dynamics of the Avacha eruptive activity is considered for a period of 1737-1991. The eruptions are classified into different types. The type and size of a future event are predicted and the related hazard is assessed. It is recommended that the southwestern and southern sectors of the Avacha surrounding should be declared forbidden for residential or industrial construction because of a high volcanic hazard. -Journal summary

Some of the previous views on the style of the Avacha eruptions during 1737-1909 are revised on the basis of new data obtained by the authors. The types of eruptions, their geological and geomorphological effects, and the related volcanic hazards are reassessed. All eruptions were explosive events, except for the 1894-1895 extrusive-explosive eruption. The eruptions of 1737, 1779, and 1827 are classified as large, the others, as mild or medium-size events. -from Journal summary