What was the largest volcanic eruption of the 20th century? Perhaps Mount St. Helens in 1980 or maybe Mount Pinatubo in 1991? The answer is actually Novarupta, a volcano that erupted in 1912 and was three times the size of the Pinatubo eruption and 30 times larger than Mount St. Helens.
The volcano is relatively unknown because of its remote location in southern Alaska, and that also means that the imagery of the area isn’t especially great. However, the NASA Earth Observatory just released an excellent image that was captured in August, 2002, that gives us a great look at the volcano.

The eruption was so massive that dust was found as far away as Puget Sound, Washington, and the ash from the volcano circled the globe and caused lower global temperatures for a year.
You can view this image for yourself inside of Google Earth by using this KML file or you can read more about the eruption on the NASA Earth Observatory site.
About Mickey Mellen
Mickey has been using Google Earth since it was released in 2005, and has created a variety of geo-related sites including Google Earth Hacks. He runs a web design firm in Marietta, GA, where he lives with his wife and two kids.
Also check out http://avo.alaska.edu/Katmai2012/
What a fantastic view of Novarupta volcano!
Congratulations for the actitude of Google Earth’s team for having posted this image, though it has not been generated by Google Earth itself.
I would love to have on the image a legend of lengh, to be able to appreciate the size
of the crater.
Best to you all,
Andre
Is there anything unique about the composition of its ash? Modern microscopy and chemical methods should reveal a much wider distribution.
Posted by Ian Donaldson at July 1, 2012 4:03 AM