Researchers suggest the megaplumes of hot water and volcanic ash produced by underwater volcanoes have a similar shape to those produced by their above-ground peers. Photo by USGS/UPI | License Photo
April 21 (UPI) -- When volcanoes deep beneath the ocean surface erupt, they release energy at rates high enough to power entirety of the United States, according to a new study published Wednesday in the journal Nature Communications.
Previously, most volcanologists assumed underwater volcanoes were much less violent than their peers on land, yielding relatively slow-moving lava flows.
But new data collected by remote-controlled submersibles in the North East Pacific suggest submarine volcanoes can generate powerful megaplumes, distributing volcanic ash across vast underwater distances.
The data showed these megaplumes are formed by large, fast-moving columns of heated water, and follow similar movement patterns to plumes produced by above-ground eruptions -- moving first upward and then spreading out horizontally.
Using the measurements captured by submersibles, scientists estimated the megaplumes generated by large underwater eruptions feature enough hot water to fill forty million Olympic-sized swimming pools.
Researchers have detected megaplumes before, but their origins remained a mystery. The latest findings are the first to link the phenomenon with the release of magma from a large underwater volcano.
To better understand the scope of these submarine eruptions, researchers developed a new computer model -- informed by both the newly acquired submersible data and measurements of ash patterns deposited by historic underwater eruptions.
Simulations showed the release of energy required to produce such expansive ash footprints was tremendous.
The largest submarine eruptions, scientists estimated, release energy at rates great enough to power an entire continent.
"The majority of Earth's volcanic activity occurs underwater, mostly at depths of several kilometers in the deep ocean but, in contrast to terrestrial volcanoes, even detecting that an eruption has occurred on the seafloor is extremely challenging," co-author David Ferguson said in a press release.
"Consequently, there remains much for scientists to learn about submarine volcanism and its effects on the marine environment," said Ferguson, a geochemist studying magmatic processes at the University of Leeds in Britain.
The new models determined magma alone can't explain the amount of energy released by submarine eruptions. Scientists estimate some of the energy release is supplied by reservoirs of hot fluids inside the crust, which rapidly empty as magma forces itself to the surface.
"Our work provides evidence that megaplumes are directly linked to the eruption of lava and are responsible for transporting volcanic ash in the deep ocean," said co-author Sam Pegler.
"It also shows that plumes must have formed in a matter of hours, creating an immense rate of energy release," said Pegler, who studies fluid dynamics at Leeds.
In the future, scientists hope to use submersibles and other remote-sensing technologies to livestream observations of submarine eruptions as they're happening.
"Efforts like these, in concert with continued mapping and sampling of the ocean floor means the volcanic character of our oceans is slowly being revealed," Ferguson said.