Forty of the world’s 800 active volcanoes are here in Alaska – and most of them are along the Aleutian Arc, extending from central Alaska along the Alaska Peninsula and down the Aleutian Islands toward eastern Russia.
This also is known as the northern portion of the Ring of Fire, where the Pacific plates meet other plates and have a lot of earthquakes and volcanic activity.
One of those volcanoes, Bogoslof, has been sporadically erupting since mid-December, and a few weeks ago, it spewed ash up 34,000 feet into the air for more than an hour and has been disrupting aircraft activity.
Volcanic activity was first recorded on Bogoslof in the mid-1790s, but the first mention of the island came from Capt. James Cook who reported seeing a tall, sail-like rock about 60 miles west of Dutch Harbor in 1778. Unbeknownst to him and his crew, a 6,000-foot volcano lay beneath the conical mountain and its crater sat just below sea level.
Early in May 1796, amid thunder, earthquake and steam, the volcanic island emerged from the depths of the sea. Otto von Kotzebue, an early Russian explorer, was told about it by an agent of the Russian-American Company at Unalaska. The agent and Natives of Umnak and Unalaska saw the birth of the island when the cataclysm occurred.
The witnesses said the island could be seen rising from the foaming waters. When the earth finally stopped shaking and flames diminished, the newly risen island, shaped like a black cap, could be seen.
The island grew in height and circumference as smoke and steam continued to pour forth. Even after eight years, Natives reported the water around the island was warm and the ground was so hot no one could walk on it.
The Aleuts called the new island Agashagok, but, since it had appeared on St. John’s Day in their calendar, the Russians called it Joanna Bogoslova, for St. John the Theologian.
Another peak estimated at 800 feet high heaved up about a mile north of the first peak in 1883. Then another eruption in 1906 brought up two more peaks, each about 400 feet tall. Within a year, these two peaks disappeared after the washing by icy waters and winds wore them down. As late as 1910 violent shocks hit Dutch Harbor, shocks probably associated with the formation of new islands in the Bogoslof group.