Boom! The Eruption of Grímsvötn Volcano

October 13, 2016

Volcanoes such as Grímsvötn are nature’s wildcard. First there is the fiery eruption , followed by the ash cloud that endangers air travel. Then the unreported final act arrives – the cold stormy winters of volcano weather.

Grímsvötn erupts—blasting through the glacier.

On May 21, the glaciers of Iceland ripped apart to reveal the angry crater of Mt. Grímsvötn. Molten lava and ice mingled in a mighty explosion. Plumes of ash and sulfur soared over 12 miles (20 km.) high in the air.

Europe winced. Volcanic ash is not soft little flakes of carbon – it is microscopic flakes of jagged glass surrounded by clouds of acid gasses. Planes that have entered these clouds have fallen like rocks. Last year’s eruption of the much smaller Eyjafjallajokull volcano stopped air traffic in Europe for 5 days.

Fortunately, Europe has updated it flight rules, so only a relatively few days of flight were lost in Iceland, Great Britain and Germany. The volcano continued to explode for five days and has finally settled back to grumpily rumbling in the glacier. As far as the news is concerned, the story is over and it is time to find something more exciting.

Grímsvötn ash cloud. Click to expand.
Source: Volcano Ash Advisory Centre—London

Here’s the unreported story. Grímsvötn was shooting out 2000 tons of ash, chemicals and steam every second! That’s a lot of pollution! Some of the material, especially the larger chunks of ash, fell back to the ground. But a lot of that stuff is still in the air. At 12 miles high, a lot of material entered the stratosphere, a quiet region of air where it will linger for over a year.

Sulfur and microscopic ash collect water and form clouds. For the next few months, the volcanic debris from Grímsvötn will be floating in the Arctic air mass. It will reflect back incoming sunlight and the polar air will grow colder.

For now we can ignore it. It’s almost summer and the polar air is far in the north. We will bar-b-que and swim and enjoy the golden warmth of the season.

Next fall, however, when the cold air begins to return, however, we will feel the extra nip in the air. The winter will be cold again and we will comment on how surprisingly stormy the weather is. We will feel that extra cold and some of us will recognize it for what it is – the last gift of a volcano in Iceland.

About This Blog

Are you a weather watcher? Welcome to “Weather Whispers” by James Garriss and until recently, Evelyn Browning Garriss. With expertise and humor, this column covers everything weather—from weather forecasts to WHY extreme weather happens to ways that weather affects your life from farming to your grocery bill. Enjoy weather facts, folklore, and fun!

With heavy hearts, we share the news that historical climatologist and immensely entertaining Almanac contributor Evelyn Browning Garriss passed away in late June 2017. Evelyn shared her lifetime of weather knowledge with Almanac editors and readers, explaining weather phenomena in conversation and expounding on topics in articles for the print edition of The Old Farmer’s Almanac as well as in these articles. We were honored to know and work with her as her time allowed, which is to say when she was not giving lectures to, writing articles for, and consulting with scientists, academia, investors, and government agencies around the world. She will be greatly missed by the Almanac staff and readers.