Alaskan Volcanoes
Written by John Carl Villanueva
Tacana Volcano
Alaskan volcanoes make up 75% of volcanoes in the US that have erupted within the last 200 years. This is understandable, being located in the Pacific Ring of Fire, the area surrounding the Pacific Ocean where earthquakes and eruptions are very frequent. Most of Alaska's volcanoes are specifically found in the Aleutian Arc, a chain of about 300 volcanic islands in the Northern Pacific Ocean.
Eruptions in Alaska, just like many eruptions in the Ring of Fire, are typically very immense. A number of them have made it to the record books.
Mount Redoubt's series of eruptions from 1989 to 1990 is the second most costly in US history, crippling the aviation and oil industries during that period.
On December 15, 1989, for example, a Boeing 747 carrying 231 passengers sucked in volcanic ash from Redoubt Volcano. As a result, all four engines conked out and the plane dropped by about 3,000 meters. Luckily, the crew managed to bring the engines back to life. That single event alone cost $80 million.
The Redoubt eruptions of 1989-1990 damaged a total of 5 jetliners. This resulted in airport closures and flight cancellations for several days.
1912's eruption at Novarupta and Katmai is considered the largest volcanic eruption in the 20th century. For 3 days, ash released into the atmosphere covered the skies in southern Alaska.
Since 1760, when volcanic activity recording began, there have been 230 confirmed eruptions. All these came from 27 volcanoes. If you try to do the math, that averages to about one eruption every year. Some small-scale eruptions have been reported but unconfirmed. If we factor these in, then there have been about 424 eruptions from 54 Alaskan volcanoes. That's nearly 2 eruptions per year.
It is believed that the number of eruptions have been increasing within the 20th century.
The organization in charge of monitoring Alaska's volcanoes is the Alaska Volcano Observatory (AVO), a joint program of the United States Geographical Survey (USGS), the Geographical Institute of the University of Alaska Fairbanks (UAFGI), and the Alaska Division of Geological and Geophysical Surveyrs (ADGGS).
We have some related articles here in Universe Today. Here are the links:
Here are the links of two more articles from Alaska Volcano Observatory (AVO):
Here are two episodes at Astronomy Cast that you might want to check out as well:
Filed under: Astronomy
Tags: Alaska Volcano Observatory, alaskan volcanoes, Pacific Ring of Fire, volcano
