What’s a ‘fumarole’?

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Increase your vocabulary and you’ll make your writing much more precise. That’s why I provide a word of the week. Today’s word: fumarole….

I live on the Pacific West Coast, in an earthquake zone. Perhaps that’s why I’m familiar with seismological terms — and mostly unfamiliar with ones related to volcanoes. (Even though some earthquakes are related to volcanoes.)

In reading the very fine first novel, Disappearing Earth, by Julia Philips, I recently came across a new volcano-related word, fumarole. Here is how she used it:

She was a universe away from the park territory its rainbow rivers, its puffing fumaroles.

fumarole  is an opening in a planet’s crust which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide. The steam forms when superheated water condenses as its pressure drops when it emerges from the ground.

Fumaroles may last for decades if they sit  above a persistent heat source; or they may disappear within weeks to months if they occur atop a fresh volcanic deposit that quickly cools. They are closely related to hot springs and geysers. A fumarole rich in sulfur gases is called a solfatara; a fumarole rich in carbon dioxide is called a mofette.

An estimated 4,000 fumaroles exist within the boundaries of Yellowstone National Park in the U.S. The photo above shows a smoking fumarole in the geothermal area Námafjall near Mývatn Lake, Iceland. 

The etymology of the word is Italian —  fumarola —  coming in turn from Late Latin fumariolum, meaningvent,” from Latin fumarium meaning “smoke chamber for aging wine.”

An earlier version of this post first appeared on my blog on Sept. 4/19.

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