A dormant volcano on the Reykjanes Peninsula of Iceland erupted late last week. It is about 20 miles from the capital city of Reykjavík and had been dormant for about eight centuries. Though small earthquakes preceded the eruption, it did not threaten human life as it was in a sparsely populated area. This eruption, like most around the world in the past century, does not compare in the least to the largest known eruption in world history.
In 1815, Mount Tambora erupted on Sumbawa Island, which is part of the Indonesian archipelago. It rated 7 on the Volcanic Explosivity Index. This index is tracked by the U.S. Geological Survey (USGS) and is based on “Volume of products, eruption cloud height, and qualitative observations (using terms ranging from ‘gentle’ to ‘mega-colossal’) are used to determine the explosivity value.” A rating of 7 is called “super-colossal.” The massive explosion of Mount St. Helens in Skamania County, Washington, in 1980 was rated at 5.
According to a description of the Mount Tambora incident by Live Science:
The eruption reached its peak in April 1815, when it exploded so loudly that it was heard on Sumatra Island, more than 1,200 miles (1,930 km) away. The death toll from the eruption was estimated at 71,000 people, and clouds of heavy ash descended on may far-away islands.
The Mount St. Helens eruption killed 57 people.
It is possible there were volcanic eruptions larger than Mount Tambora. They were too long ago for scientists to measure accurately. One was on the Deccan Plateau in India, over 60 million years ago. It may have triggered the extinction of many of the world’s dinosaurs. Another eruption too old to measure happened in what is now known as Yellowstone National Park about 640,000 years ago.
Mount Tambora remains an active volcano, which means that it could erupt again.