Novarupta The Most Powerful Volcanic Eruption of the 20th Century

une 6th, 1912


The morning of June 6th arrived on the Alaska peninsula to find the area which is now Katmai National Monument being shaken by numerous strong, shallow earthquakes. The most powerful volcanic eruption of the 20th Century was about to begin – but very few people knew about it. The Alaska peninsula has a low population density today but it 1912 it was even lower. Beyond the land shaken by the earthquake activity the beginnings of this event were almost unnoticed.

Volcanic Monitoring - 1912 vs. Today


Today the stirring of an important volcano draws enormous global attention. Weeks or even months before most large eruptions a buzz circulates through an electronically-connected community of volcano scientists as clusters of small earthquakes are detected by a global array of seismographs. Many scientists working at diverse global locations interpret this data and begin to collaborate about an awakening volcano and the eruption that might follow. Reports are posted on the internet and news stories communicate the volcano's activity to millions of people. Often it is a false alarm – the volcano is simply stirring.

If the earthquakes strengthen and begin moving upwards, many of these scientists will travel to the area of potential eruption to make observations and set up a local network of data-gathering instruments.

However, in 1912, Alaska was not a US state, very few scientists were supported to do volcanic studies and a worldwide network of seismic monitoring was not in place. Scientists were just starting to understand the mechanics of volcanic eruptions.

Novarupta Volcano Erupts!


On June 6th, 1912 a tremendous blast sent a large cloud of ash skyward and the eruption of the century was underway. People in Juneau, Alaska, about 750 miles from the volcano, heard the sound of the blast – over one hour after it occurred.

For the next 60 hours the eruption sent tall dark columns of tephra and gas high into the atmosphere. By the time the eruption ended the surrounding land was devastated and about 30 cubic kilometers of ejecta blanketed the entire region. This is more ejecta than all of the other historic Alaska eruptions combined. It was also thirty times more than the 1980 eruption of Mount St. Helens and three times more than the 1991 eruption of Mount Pinatubo, the second largest in the 20th Century.

The rest of the peice is here:

[link to geology.com]