STEPAN KRASCHENINNIKOW (1711-1755)
Opala volcano (2,475m-8100 ft)
Russia (Kamchatka)
In Mountains of Kamtschatka, St Petersbourg 1755
The volcano
Opala
(Опала) (2,475m-8100 ft) is a large stratovolcano located in South
Kamchatka about 50 km west of the Eastern volcanic front. The volcano
sits on the northern rim of a 14x12 km large Late Pleistocene caldera.
The summit of the volcano has a nice small crater. The most prominent
feature at the foot of the volcano is Baranii Amphitheater - a large
Novarupta-type crater filled with extrusive domes. This crater formed
about 1500 years BP and produced 9-10 km3 of rhyolitic pumice that is
about 4.5 km3 of magma. Later the crater was filled with extrusive
domes. There was at least one later eruption within the crater, which
formed explosive craters on the surface of the extrusive domes and
produced minor pumiceous tephra. Several hazy reports of Opala's
historical eruptions were known, but no real evidence of recent
eruptions had been found at the slopes of the volcano. However, later
studies have allowed to document a significant explosive eruption from
the summit crater, which occurred as recently as about 300 years ago and
produced rhyolitic tephra (informally known as "Ghost layer").
Earlier eruptions from Opala produced lava flows and pumiceous tephra.
The eruption from Baranii Amphitheater was one of the most voluminous
explosive eruptions in Kamchatka during the Holocene. Opala is
undoubtedly an active volcano posing a serious hazard to the region.
Recent eruptions from Opala produced dominantly rhyolitic material that
indicates a presence of living silicic chamber under the volcano.
Holocene products of Opala volcano are high potassic
andesites-rhyolites. Baranii Amphitheater crater produced uniform
rhyolites without any admixture of more mafic varieties. Opala volcano
has been producing andesitic-dacitic lavas and tephras for most of
Holocene; the last significant eruption of this kind was ab. 3500 14C
yrs BP. How was it possible to produce, accumulate, store and finally
erupt - just in a couple of millenia - about 4.3 km3 of rhyolitic magma
from the crater located on the volcano's slope, a mere 5 km from its
summit? Was the OP eruptionit a part of the Opala volcano story or any
special event? Why is this magma so similar to Chasha crater's one,
stored 15 km away? These are genral questions to this volcano.
The artist
Stepan
Petrovich Krasheninnikov (Степа́н Петро́вич Крашени́нников) was a
Russian explorer of Siberia, naturalist and geographer who gave the
first full description of Kamchatka in the early 18th century. He was
elected to the Russian Academy of Sciences in 1745. The Krasheninnikov
Volcano on Kamchatka is named in his honour. He embarked upon the Second
Kamchatka Expedition (1731–42). Krasheninnikov was to study plants,
animals and minerals, but in addition he developed a strong interest in
Siberian history and geography. During the early part of the expedition,
he accompanied professor Gmelin on the travel through the Urals and
western Siberia to Yeniseysk. He made numerous observations of natural
history, ethnology and linguistics, e.g. records of Evenki (tungus) and
Buryat vocabulary. From Bering’s headquarters at Yakutsk, the expedition
professors Gmelin and Gerhard Friedrich Müller sent Krasheninnikov
ahead to Okhotsk and Kamchatka to build house and make preliminary
observations. Thus, he became the member of the expedition with the most
extensive knowledge of the peninsula. He published his observations in
1755 (Описание земли Камчатки); English translation by James Grieve
(1764) as History of Kamtschatka. However, he drew extensively on
the manuscripts of the deceased Georg Wilhelm Steller. Apart from
detailed accounts of the plants and animals of the region, there also
were reports on the language and culture of the indigenous Itelmen and
Koryak peoples, with whom he is said to have got along extremely well.
Krasheninnikov spent ten years on the Second Kamchatka Expedition. On
his return to St Petersburg, he wrote and defended his doctoral thesis
on ichthyology in 1745. He was appointed adjunct at the Academy of
Sciences, and later head of the Academy's Botanic Garden and professor
of natural history at the university. He was one of only 26 Russians to
become Academy members in the 18th century. In 1752, Krasheninnikov went
on his last expedition to the tracts of Lake Ladoga and Novgorod to
investigate the flora. He died before being able to publish his
observations, which instead were published by David de Gorter.
