The eruptive history of Ebeko since its arising about 2400 years ago to the beginning of the 17th century was reconstructed based on data of special geological, gecmorphological, tephrochronological researches using the 14С dating (more than 20 dates). Six stages of increased activity with the duration of 200-300 years were recognized. These stages are divided by quiet periods of the same duration. It is shown that the eruption of juvenile material (lava and pyroclastic) took place only at the first stage (420-200 years before our era). All the next eruptions were phreatic, but of different power. Large-scale maps and lopoplans of the Ebeko volcanic group (Ebeko, Neozhidanhy, Nezametny) with the nearest areas were compiled and the present-day morphology of the Ebeko summit part was described m detail based on ariborne materials of 1987, 1988, 1990. It is presented that, not considering the first eruptive stage, the main volcanic hazard for the Ebeco region and the town of Severo-Kurilsk situated near the volcano came from the moving of large lahars and tephra fall.

Consequences of the Ebeko eruptions in 17-20 centuries were reconstructured in detail based on history information and data of tephrochronoSogical investigations and air photography of 1960, 1987, 1988, 1990. It is shown that all the eruptions were phreatic and conditionally phreatomagmatic with thermal alimentation as a very heated dike-sill complex with volume of more than 1 km , in the zone of extension NNW (Az. 25°), where volcanoes of the Vernadsky ridge are located (Paramushir island). It is supposed that the main future hazard for the Severo-Kurilsk town and the nearest areas is expecting from the moving of lahars of large-volume along the Kuzminka and the Matrosskaya rivers originated from the Ebeko volcano. Lesser hazard is expecting from ashfalls produced by the Ebeko and other volcanoes of the North Kuril and the Souih Kamchatka. It is proved that a big hazard for the may arise from the future eruption of the Ebeko similar to those eruptions of 1934-1935. It is recommended some ways for defence of the town.

The devestating explosive eruptions at Khangar (about 7000 14C BP), Khodutkinskiy "maar" (about 2800 14C BP), and Baraniy Amphitheater (about 1500 14C BP) are classified into a special type, subcaldera eruptions. They were analogues of caldera-forming eruptions by their dynamics, erupted volume (1.5-15 km^3), aspect, facies family, and the composition {from dacites to rhyolites) of the pyroclastics, but were not followed by the development of collapse calderas whose cavity volumes would fit the volume of discharge pyroclastics when converted to solid rock (magma). The discrepancy between a "caldera-like" aspect of the pyroclastics and the type of erupting vent can probably be explained by the greal depths of reservoirs of silicic magma which were "galvanized" when hot basaltic magma was injected into them. A subcaldera eruption usually began with a violent discharge of tephra, much greater in volume than the other volcanic products, to be followed by the formation of pyroclastic flows associated with pyrociastic surges. This sequence of events repeated itself several times during the eruption. No major explosion breccias were formed. Intensive ashfall involved areas of n * 10^4 ... n * 10^5 km^2, so that dated tephra beds have been excellent regional marker horizons. Subcaldera eruptions are hypothesized to have influenced the Earth's climate and are reflected as synchronous acid peaks in the Greenland glacier shield.

The 1645 B.C. oxygen peak in Dye 3 borehole (65.18 N, 43.49 W) drilled in the Greenland ice sheet is shown to have been the catastrophic caldera-generating Aniyakchak eruption (56.88 N, 158.17 W) on Alaska Peninsula, U.S. rather than the famous Minoan eruption (36.404 N, 25.396 E) on Santorin Island, Greece.

This stady has proved that the EPR technique can be used to date volcanic formations within the Elbrus Volcanic Center (EVC) by investigating rock-forming quartz in volcanites, xenoliths of Paleozoic granite contained in these, and quartz in underlying older, metamorphic lavas. This is the firts time in Russia that the EPR dating technique has corroborated cycles of activity in the behavior of the Elbrus Volcanic Center previously identified from geological data, has determined the relevant time intervals, and deciphered the history of this stratovolcano. It is for the firts time that the EPR technique was used to determine the timing of paleofumarole activity and the age of deposits left by paleothermal springs (geyserites) during the EVC history. EPR dating results yielded a much earlier beginning of activity for Elbrus Volcano (mid-Middle Neopleistocene, 220.000 to 200.000 B. P.) and accordingly, a shorter duration compared with the opinion of previous researchers who based their findings on the K-Ar technique and the geomorphic method.

The first paper in the series “The 300 Years of Kamchatka Volcanoes” has examined the 350-year eruptive history of Young Shiveluch Volcano, which is the northernmost of the active volcanic edifices in Kamchatka: the history was reconstructed from historical documents and evidences, results of geological volcanological research and tephrochronologic dating as well as the 14C method. The results include the types, parameters, geologic-geomorphologic effect of the volcano’s eruptions, environmental impact, estimated volume and weight of erupted and redeposited material, the volcano’s discharge rate. Since 1964 the sizes of the new volcanic forms, the dynamics of their growth and destruction, and the volume of ejecta were calculated using photogram-metric techniques. Part II. 1965-2000.