8/23/2023 0 Comments Parkdale earthquake oregonThis is the first known site of its kind, Solomon said. That's bad news for earthquake hazards: Less lubricant means stress can build to create a damaging quake. If the fluid pressure is lower, the two plates will lock - that's when stress can build up."įluid released from the fault zone is like leaking lubricant, Solomon said. "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. "The megathrust fault zone is like an air hockey table," Solomon said. Loss of fluid from the offshore megathrust interface through these strike-slip faults is important because it lowers the fluid pressure between the sediment particles and hence increases the friction between the oceanic and continental plates. These strike-slip faults, where sections of ocean crust and sediment slide past each other, exist because the ocean plate hits the continental plate at an angle, placing stress on the overlying continental plate. Instead, they occur near vertical faults that crosshatch the massive Cascadia Subduction Zone. The new seeps aren't related to geologic activity at the nearby seafloor observatory that the cruise was heading toward, Solomon said. Calculations suggest the fluid is coming straight from the Cascadia megathrust, where temperatures are an estimated 150 to 250 degrees Celsius (300 to 500 degrees Fahrenheit). Observations from later cruises show the fluid leaving the seafloor is 9 degrees Celsius (16 degrees Fahrenheit) warmer than the surrounding seawater. The feature was discovered by first author Brendan Philip, who did the work as a UW graduate student and now works as a White House policy advisor. That's something that I've never seen, and to my knowledge has not been observed before," said co-author Evan Solomon, a UW associate professor of oceanography who studies seafloor geology. "They explored in that direction and what they saw was not just methane bubbles, but water coming out of the seafloor like a firehose. Further exploration using an underwater robot revealed the bubbles were just a minor component of warm, chemically distinct fluid gushing from the seafloor sediment. The ship's sonar showed unexpected plumes of bubbles about three-quarters of a mile beneath the ocean's surface. The team made the discovery during a weather-related delay for a cruise aboard the RV Thomas G. Observations suggest the spring is sourced from water 2.5 miles beneath the seafloor at the plate boundary, regulating stress on the offshore fault. 25 in Science Advances, describes the unique underwater spring the researchers named Pythia's Oasis. A study led by the University of Washington discovered seeps of warm, chemically distinct liquid shooting up from the seafloor about 50 miles off Newport, Oregon.
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