Kavachi, a submarine volcano in the southwest Pacific Ocean, is home to several species of sharks and fish that can withstand the extreme environment
Sarah KutaMay 25, 2022
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An underwater volcano surrounded by sharks sounds like something out of a science fiction movie, but “Sharkcano” is very real—and, according to new images captured by satellite, it’s erupting.
NASA’s Operational Land Imager-2, located aboard the Landsat 9 satellite, took striking snapshots of the submarine volcano, called Kavachi, erupting earlier this month. Amid the inky blue waters of the southwest Pacific Ocean, a greenish cloud of superhot, acidic water billows from the submarine volcano.
Named after a sea god of the Indigenous Gatokae and Vangunu people, Kavachi is located about 15 miles south of Vangunu Island, part of the Solomon Islands east of Papua New Guinea. It’s one of the most active underwater volcanoes in this part of the Pacific and has been erupting nearly continuously since at least 1939, when people living on nearby islands first recorded an eruption, according to the Smithsonian’s National Museum of Natural History Global Volcanism Program.
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The volcano is also known by the name Rejo te Kvachi, which means “Kavachi’s Oven”—a fitting moniker for the superheated lava, steam, particulates, rock fragments and sulfur that sometimes reach the water’s surface. Scientists believe the volcano’s summit is roughly 65 feet below the water; Kavachi’s base is on the seafloor, about three-fourths of a mile below sea level, per NASA.
Over its recorded history, Kavachi has created a handful of ephemeral islands that have spanned up to a kilometer in length. But the ocean’s waves have always eroded and washed these islands away. It also produces dramatic phreatomagmatic eruptions, in which superheated magma and water interact to create violent, steamy explosions.
“Sharkcano” earned its nickname after a 2015 expedition found two species of sharks, along with active microbial communities, living within the volcano’s crater. Using a baited drop camera, an international team observed scalloped hammerhead sharks (Sphyrna lewini) and silky sharks (Carcharhinus falciformis) living in the hot, acidic water. Kavachi is a “fascinating natural laboratory” that “remains full of mysteries to explore,” according to the researchers, who published the results of their exploration in the journal Oceanography in 2016. NASA has been tracking Kavachi for some time, taking equally spectacular photos of eruptions in 2007 and 2014.
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“Surprisingly, this hostile environment hosts a vibrant ecosystem, including gelatinous zooplankton, reef fish and sharks,” they wrote in the paper. “The presence of these animals in such extreme conditions poses new questions centered on the resiliency of marine animals to rapid changes in their environments… do these groups have a greater chance of surviving human-induced changes to ocean chemistry and periods of increased submarine volcanism on a global scale?”
These and many other research questions prompted by “Sharkcano” remain unanswered, at least for now. But in the meantime, the mysterious geomorphological feature—with sharks prowling around its treacherous, lava-spewing vent—continues to pique the imaginations of people around the world.
