Lubricant leaks from the sea floor and may increase the risk of earthquakes

[ad_1]

Scientists have detected a strange, warm fluid spewing from the seafloor “like a firehose” near Oregon, and suspect it could provide some hints about earthquake activity in the Pacific Northwest.

Researchers led by the University of Washington dubbed the first-of-its-kind discovery the Pythia Oasis. Located about 80 kilometers (50 miles) off the coast of Newport, the team used the ship’s sonar to identify unexpected columns of bubbles emerging from the sea floor, about 1.2 kilometers (three-quarters of a mile) below the ocean’s surface.

Upon further investigation, it was revealed that the fluid flowing from the sea floor was chemically different from the surrounding water, containing “significant” amounts of boron and lithium, but significantly less chloride, potassium, and magnesium.

“They explored in that direction and what they saw wasn’t just methane bubbles, but water coming out of the sea floor like a firehose. This is something I’ve never seen before,” Evan Solomon, study co-author and associate professor of oceanography at the University of Washington, said in a statement. To my knowledge, it has not been observed before.

Even stranger, the liquid was about 9 degrees Celsius (16.2 degrees Fahrenheit) warmer than the background temperature. The stark difference in temperature indicates that the liquid originated from the Cascadia megathrust deep below Earth’s surface, with temperatures ranging from 150 to 250 degrees Celsius (300 to 500 degrees Fahrenheit).

The massive Cascadia subduction zone lies on a fault line between two giant tectonic plates. Given the deep subterranean origins of this warm fluid, the team suspects that this fluid plays a role in Earth’s ever-changing tectonic activity.

Solomon suggests that the fluid that comes out of the fault area is somewhat like a lubricant, reducing friction between the plates and allowing them to glide gently against each other. As such, leaking lubricant can be a worrying sign that the tension between the plates is increasing, increasing the potential for an earthquake.

“The giant fault zone is like an air hockey table,” Solomon explained. “If the fluid pressure is high, it’s like running air, which means there’s less friction and the two plates can slide. If the fluid pressure is lower, the two plates will lock — then pressure can build up.”

While these strange springs seem hard to spot, researchers suspect there are others nearby. If it’s a common feature, perhaps they can overtake scientists with some insights into tectonic activity and even earthquake risk.

“The Pythia Oasis provides a rare window into the processes working deep on the sea floor, and its chemistry indicates that this fluid is coming from near plate boundaries,” added co-author Deborah Kelly, a professor of oceanography at the University of Washington. “This indicates that nearby faults regulate fluid pressure and massive slip behavior along the Cascadia central subduction zone.”

The study was published in the journal Science Advances.

[ad_2]