fyoo-muh-rohl | /ˈfyu məˌroʊl/
Fumaroles are the billowing, somewhat sinister vents emblematic of volcanic landscapes. Derived from the Latin fumariolum, meaning smoke hole, they don’t actually emit smoke but gases – usually steam, carbon dioxide, sulfur dioxide, hydrogen sulfide, and chloride – in potentially lethal quantities. Dangerously unpredictable, they are portals to an infernal underworld of immense and sometimes deadly explosive power.*
Fumaroles are typical of late-stage volcanic activity where the magma has begun to cool and solidify, hence they are sometimes called dying volcanoes. They may disappear after just a few days or last for decades. In Yellowstone National Park, one of the hottest vents, known as the Black Growler, is believed to have been billowing superheated steam for at least 140 years. For volcanologists, a vent’s temperature, gases, and emission rates is a relatively accessible window into what’s happening under the ground, helping them predict the likelihood of future eruptions.
Fumarole fields can be vast – in Alaska, the Valley of Ten Thousand Smokes covers an area of over 100 square kilometres. Created by an enormous eruption in 1912, the remote site wasn’t discovered until 1916, whereupon it was found to be blanketed in a thick layer of volcanic ash teeming with thousands of fumaroles.
In 2012, researchers flying over the site of the infamous Mount St Helens eruption** made another startling discovery. Having noticed what appeared to be a geothermal vent in the crater’s recently formed glacier, a 2014 expedition into what became known as Godzilla Hole found fumaroles had carved out an extensive cave system of huge chambers and steep tunnels within the ice.
* A year after the photo on the right of New Zealand’s Whakaari/White Island was taken, the crater erupted with the loss of 22 lives.
** The 1980 eruption of Mount St Helens was the deadliest in United States history, claiming 57 lives.
Introduction Aeolian Alpenglow Apricity Asperous
Benthos Crepuscular Crispate Crown shyness
Desire lines Dreich Endragoned Edgelands
Frondescence Fumarole Gluggaveður Gossamer
Karst Komorebi Lawrence Long acre
Machair Monkey’s wedding Moonglade
Psithurism Quartz Rakuyou Roaring forties
Snag Soft estate Specular, diffuse and pellucid
Spoondrift Steam fog Swash zone Sylvan