Volcanic eruptions are fairly common, blowing every few decades, or in some cases, every few centuries, sending fiery ash and debris skyrocketing into the air.
But land-based volcanoes make up only a small fraction of the eruptions that take place. When a young volcano known as Axial Seamount off the coast of Oregon threatened to blow after its caldera spent several months contracting and signaling, it was a big clue that it was about to explode. This time volcanologists were ready.
Running a billion-dollar network of fiber-optic cables and seismometers along the ocean floor, they were able to map the size and spread of the volcano’s magma chamber as the volcano loaded its metaphorical barrel and to watch the eruption in real-time.
They watched the caldera at the top of the volcano swell like a balloon filling with air, building up pressure until it finally burst. The eruption, when it came, was dramatic.
On the morning of April 24, 2015, the sea floor literally split open and the volcano erupted after a large crack caused by the rising seafloor allowed the pressurized magma to roar out of the breach.
In under an hour there were over 600 earthquakes that demolished the sea floor - the scientists estimated than more than 79 billion gallons of scorching hot magma had the icy water, exploded, and instantly solidified into new rock.
To capture it on film was said to be a triumph for scientists and pyrotechnics enthusiasts alike.
“We only know about a dozen eruptions on the sea floor,” said David Clague, a volcanologist at the Monterey Bay Aquarium Research Institute. “Most of the world is not instrumented, and so they happen in solitude and no one knows. They are definitely the tree falling in the forest that no one hears.”
University of Washington oceanographer William Willcock, the lead author of one of the new studies on the eruption that was just published in the journals Science and Geophysical Research Letters, said these are “the most detailed observations ever made” of an undersea volcano. They may well be among the most detailed observations of any eruption on land too.
Scientists around the world hope to take what we learned during Axial Seamount’s eruption and apply it to other “hot spots” around the world to track the seismic activities of other volcanoes.
Find out more by watching the footage below: