Scientists Unravel the Mystery Behind Strange Holes Spewing Warm Fluids on the Pacific Ocean Floor

Like the crooked pieces of a jigsaw puzzle, the tectonic plates embedded in Earth’s crust constantly dance and jiggle, often birthing new volcanoes and mountains. The mysterious nature of this plate tectonics has proffered geologists a wealth of secrets about what’s going on within the innards of the planet. Among these secrets, the most fascinating ones pertain to the plates sitting at the bottom of seas and oceans. As per NOAA, when these underwater plates crash, collide, or smash into one another, they reveal hotbeds of molten lava or hypothermal vents spewing vortices of assorted chemicals.

In 2023, graduate student, Brendan Philip, was onboard a research cruise that got delayed due to weather. As he waited for the cruise, he suddenly noticed several columns of bubbles spuming from about three-quarters of a mile beneath the ocean’s surface, as if a bottle of fresh soda had been uncorked somewhere down in the deep. Further investigation with an underwater robot revealed that the bubbles weren’t fizzing upwards from a hypothermal vent. Something unusual hiding at the seafloor was sending these bubbly spumes up at the surface.

In a research published in the journal Science Advances, the team later revealed that this portion of the Pacific Ocean has a leak, and holes in this leak are ejecting gushing plumes of warm, chemical-sopped fluids into the ocean water, just like a “firehose”. They named the leak “Pythia’s Oasis,” based on Greek folklore. The discovery was made around 50 miles off the coast of Oregon, mainly in the Cascadia Subduction Zone (CSZ), off the coast of Washington. The CSZ is a "megathrust" fault a 1,000 km long dipping fault that stretches from Northern Vancouver Island to Cape Mendocino California, according to Pacific Northwest Seismic Network. In the past century, the zone has triggered massive earthquakes of magnitude 9 and higher and will continue to do so as per experts.

Evan Solomon, a University of Washington professor who studies seafloor geology compared CSZ to a “hockey table.” “If the fluid pressure is high, it’s like the air is turned on, meaning there’s less friction and the two plates can slip. If the fluid pressure is lower, the two plates will lock – that’s when stress can build up,” Solomon said in the university press release. In this case, the warm fluid emitted by the fault is acting as a tectonic lubricant that moisturizes the crusty plates on the seafloor.

“The seep fluid chemistry is unique for Cascadia and includes extreme enrichment of boron and lithium and depletion of chloride, potassium, and magnesium. We conclude that the fluids are sourced from pore water compaction and mineral dehydration reactions with minimum source temperatures of 150° to 250°C,” the researchers noted in the paper. After Pythia’s Oasis was first discovered, the scientists investigated the leak with advanced instruments. The plumes emitting out of the leak didn’t contain any territories of creatures like ghostly fish, tube worms, or shrimp, unlike the hydrothermal vents where these creatures thrive on the seeping chemicals. Instead, this leak was a “spring” that was spouting jets of chemical liquid into the ocean. 

Solomon explained that this eerie chemical leak is not good for the planet as it can rapidly heat up the Pacific Ocean water, putting extreme stress on the continental plates, which could trigger an earthquake as intense as magnitude 9. But the team still doesn’t know how long this leak stretches out in the crust. "It's somehow draining or partly draining the fault," Demian Saffer, director of the University of Texas Institute for Geophysics, who was not involved in the research, told Live Science. "What we don’t know is how big an area that's happening, and we also don't know how much that's changing the pressure and stress on the fault. … Those are the kinds of things that would be natural next steps to try to figure out."