Recent Changes in Bogoslof Volcano

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. American Geographical Society is collaborating with JSTOR to digitize, preserve and extend access to Geographical Review. Sea, on the inner side of the Aleutian arc, is an unusual type of volcano, with pillar-like islands occasionally rising from the sea only to be in part or wholly destroyed by explosions. Since the earliest voyagers appeared in Bering Sea during the latter part of the eighteenth century, six islands have appeared, of which only three remain. These three peaks are now connected by sand bars and by the products of various volcanic explosions to form a single island.The formation of the first island, Ship Rock, was reported by the earliest navigators about 1768, and the rock was not washed away by the powerful wave-attack of the open ocean until 1888. Old Bogoslof, now known as Castle Rock, was pushed from beneath the sea in 1796 as a solid rocky mass 4,000 feet in diameter and 350 feet in height. New Bogoslof (Grewingk or Fire Island) appeared in 1883 on the other side of Ship Rock from Old Bogoslof. The new island rose precipitously out of the sea to a height of over 800 feet, showing that it had been pushed out of an orifice in a very pasty condition instead of being formed of lava flows or ash which might accumulate around a crater.Between 1883 and 1906 many changes took place in the forms of both Old and New Bogoslof, but no other islands were formed until March, 1906. In this month an island 2,000 feet in diameter and 400 feet in height appeared between Old and New Bogoslof. The names Perry Peak and Metcalf Peak were both given to this rock. The sides of the mass were described as being quite smooth and the top had the form of a "broken horn" as if the whole mass had been forced through an opening in the top of the submarine volcano. In the winter of 1906-07 half of Perry Peak was blown away and another spinelike mass rose not far away from the shattered side of Perry Peak. The new rock, McCulloch Peak, was about the same size and had the same form as the original Perry Peak, and, like the latter, was destroyed by an explosion ten months after its appearance, in September, 1907. Since this time nothing appears to have been published concerning the evolution of the volcano, and it is the aim of this paper to present what little information has been procured from the reports of government vessels.1 I The early history of the volcano is described by C.

Historical eruptions and hazards at Bogoslof volcano, Alaska

“…This period of eruptive activity was also associated with sustained steam emission and the eventual emplacement of a lava dome or domes (Old Bogoslof/Castle Rock) extending as much as 350 ft above sea level. during September 1907-July 1908 activity Large dome of water, vigorous steaming, ash emission, and lava effusion reported on July 7, 1908 Jordan and Clark, 1906Jaggar, 1908bDunn, 1908Munger, 1909Prosser, 19111909-1910 Powers, 1916Morris, 19361926 Local observers report explosive activity on July 17, 1926 Significant steaming observed in late July 1926 Black smoke, fire, muddy water, and lightning observed on August 12, 1926 Submarine explosions reported during summer-fall 1926 Lava dome effusion and ring of explosion debris reported during winter . Lava dome about 60 m high and 300 m in diameter.…”

“…By September 1909 the open embayment observed in 1908 ( fig. 35) had been closed off, forming a lagoon (Powers, 1916), probably as a result of wave erosion of the tuff ring that connected Old and New Bogoslof. In addition, two small "islands" were present in the lagoon as of September 1909, one of which was steaming (Powers, 1916).…”

“…35) had been closed off, forming a lagoon (Powers, 1916), probably as a result of wave erosion of the tuff ring that connected Old and New Bogoslof. In addition, two small "islands" were present in the lagoon as of September 1909, one of which was steaming (Powers, 1916). Observations made on June 16, 1910, indicate that the two islands in the lagoon continued to grow and eventually merged to form a single lava dome that stood about 178 ft (54 m) above sea level (Powers, 1916).…”

Changes in Marine Bird and Mammal Populations on an Active Volcano in Alaska

“…By 1973 Bogoslof consisted of Castle Rock, a remnant of the 1796 eruption, with two peaks, 110 m and 50 m tall; a 12-ha plateau formed by the eruptions of the early 1900's, surrounded by sand and (1787) Grewingk (1850), Dall (1870) Grewingk (1850) Dall (1884) Merriam (1910) Jaggar (1908). Powers (1916), Byers (1959) Jaggar (1930) Hottel ((1927), Jaggar (1908), Byers (1959) Byers (1959) Byers ( Figure 3 shows Bogoslof as it appeared in 1973.…”

Geology of Umnak and Bogoslof Islands, Aleutian Islands, Alaska

“…Jaggar (1908 published a history of Bogoslof and an account of his landing of August 7, 1907, Robert Dunn visited both Bogoslof and northeastern Umnak and was the first (Dunn 1908) to publish the' name Okmok, supposedly the native name for this volcano. Sidney Powers (1916) gave an account of the 1910 eruption of Bogoslof and the extrusion of the Taboma Peak dome and Jaggar (1930) gave an account of the 1926-27 Bogoslof activity. Lukens (1936) -gave a description of Bogoslof Island as it was in 1935.…”