Event Name : Bogoslof 1806
Start: | 1806 | Observed | ![Information derived from: Grewingk's geology of Alaska and the Northwest Coast of America [edited by Marvin W. Falk, translation by Fritz Jaensch published 2003]](/images/icons/report.png) |
Stop: | 1823 | Observed | ![Information derived from: Notes on the islands of the Unalaska district [translated from Russian by Lydia T. Black and R.H. Geoghegan in 1984]](/images/icons/report.png) |
"Smoke": |
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Lava flow: |
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Tephrafall: |
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Lava dome: |
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Eruption Type: | Explosive | |
MaxVEI: | 2 |
![Information derived from: Volcanoes of the world [2nd edition] BibCard](/images/icons/report.png) |
Duration: | 7 years |
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Description: Dall (1884) writes: "In 1806 fissures appeared, lined with crystals of sulphur. According to Langsdorff, who saw it in this year, it did not exhibit any special activity, though steam and smoke arose more or less constantly. In this year three baidarkas visited the island. On the north side soft lava flowed into the sea, and it was too hot to approach closely; but on the southern end a landing was effected. The peak was too sharp and rugged to be ascended, and the rock was very hot. A piece of seal meat suspended in a crevice was thoroughly cooked in a short time. There was no soil or fresh water." Langsdorff reported the size of the island in 1806 as 10-15 versts in circumference, and 2,500 feet in elevation.
Grewingk (1850, translated 2003 by Fritz Jaensch) reports that Baranov reported the following in 1814 (possibly 1804?): "On the first of June, 1814, a baidarka was launched to observe the phenomenon from a closer proximity. When its occupants had approached to a distance of five versts, a violent current was observed between the pointed blind cliffs. In spite of this it was possible to go ashore at a very low point, where sea lions had occupied the rocks in large numbers. It appeared that the island consists entirely of precipices, covered with small rocks, which are continuously expelled from the crater. They obscure the view and nearly cover the entire surface of the island. Therefore it was impossible to make investigations on land. It was instead decided to sail around it. Nowhere could sweet water be found. In the year 1815 (1805?) a second expedition was sent to the island. This time the island was found to be much lower in elevation than in the previous year. The bad weather forced the people to remain there for six days. A very strong current flowed continuously around the island. The physiognomy of the island had changed completely. There were ravines filled with masses of rock, which continuously collapsed, whereupon new precipices opened up."
In 1816 and 1817, Grewingk (1850, translated 2003 by Fritz Jaensch) writes that Eschscholtz reported no activity at Bogoslof. Grewingk (1850, translated 2003 by Fritz Jaensch) also reports that Dr. Stein reported smoking at Bogoslof in 1820: "And from the highest point of the mountain - which I call Kruzenstern Volcano - there arose, probably from the crater, columns of smoke (not fire). From a crevice at the foot of the mountain, a spring sprouted up in an arch like a waterfall. The entire island is a bare and barren rock; and only in a few places was there still snow, covered, it seemed, with volcanic ash. On the sketch there appears on the right sides Cook's "Ship Rock," which is much favored by the birds. And the island St. J. Bogoslof presents the spectre of deep fissures and lava streams (ispeshchren), traversing its surface. Its circumference amounted to 4 Italian miles (7 versts), and the elevation 500 ft., Engl., above sea level."
Veniaminov (1840, translated 1984) writes that "At last in 1823 it noticeably ceased either to grow or to erode. From the time of its appearance and until it ceased to increase in size, it was so hot that steam always rose from it and, at first, even the sea water around it was warm."
Newhall and Melson (1983) estimate the size of this lava dome to be about 10x10^6 cubic meters.