Recent studies of scientists from the Institute of Volcanic Geology and Geochemistry (Far Eastern branch of the Russian Academy of Sciences) have resulted in another potentially active volcano appearing on the map of the peninsula. Scientists have previously considered the last eruption of the Khangar volcano, which was also thought to be the only one eruption of said volcano, had happened in Holocene about 7 thousand years ago, and its consequences were catastrophic. However, thorough geological and chronological analysis of rocks surrounding the volcano, which was considered to be extinguished, showed not less than 10 layers of ash and other erupted materials, the most recent of which is aged 400 years..

According to existing scientific classification potentially active volcanoes of the Kamchatka peninsula must have at least one eruption over the last 3 or 4 thousand years. The peninsula boasted 28 active volcanoes and 160 dormant volcanoes, until scientists made the discovery described above. From this moment the Ichinskaya Sopka volcano, which was thought to be the only active volcano of the Sredinny (Middle) Range of Kamchatka, has a companion – the Khangar volcano. To find out the truth scientists have performed a huge set of complex experiments – they needed to make sure that previously erupted rocks and ashes belonged to the Khangar volcano. They have finally succeeded in proving that the Khangar volcano was an active one by defining the composition of volcanic material and thickening of its bands while getting closer to the dormant volcano. Ashes of the Khangar volcano were identified by biotite mineral, which is a characteristic feature of this very volcano – biotite is never found in ashes of neighbouring volcanoes.

After that researchers have performed radiocarbon analysis of over fifty samples of volcanic material, which allowed defining the age of previously unknown Holocene eruptions of the volcano. The Khangar volcano appeared to have two active periods in the recent geologic period. Besides the eruption, which happened 7 thousand years ago, there also were powerful explosions, forming a giant 6 square km crater, dated 10 and 6.5 thousand years ago. The last of said eruptions has marked the end of early active period of the Khangar volcano.

After a long period of dormancy the volcano has woke up 4.5 thousand years ago. Since that eruption scientists have detected several weaker eruptions, which happened 4 thousand, 2.5 thousand, 1 thousand and 400 years ago. Scientists admit the possibility of even weaker explosions, which could have happened during relatively quiet period of the volcano, which lasted between 500 and 2500 years. While first eruptions of this active period consisted mainly of pumice, volcanic sand and dust, two most recent eruptions have thrown mainly ashes, consisting of yellow and grey arena gorda (coarse sand and gravel), out of volcano funnel.

Most recent eruptions of the Khangar volcano have resulted in piles of hardened lava, which geologists use to call extrusions. Currently the crater of the Khangar volcano hosts a lake, which is over 150 m deep – one of the above mentioned dome structures, looking like three closely located small islands, can be seen above the lake surface.

Considering discovered dates of recent eruptions of the Khangar volcano, scientists have classified the volcano as potentially active volcano, which now is relatively dormant. They have even given a definition to most probable type of future eruption – phreatomagmatic, which means that erupted volcanic material will interact with lake waters. Scientists also predict that future volcanic eruption brings no instant threat to lives of human beings inhabiting the area, because human settlements are located far from the volcano. However, the explosion may have catastrophic impact on the environment. Even small eruption may cause catastrophic mud flows: weak eastern wall of the crater may break releasing the lake, which contains about 0.4 cubic kilometers of water.

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Kizilova Anna