By the end of this year, mysterious and highly active undersea volcanoes on the Pacific coast may erupt, scientists say.

The volcano, known as Axial Seamount, is nearly a mile deep and about 700 miles northwest of San Francisco, is under increasing scrutiny of scientists who discovered its existence only in the 1980s.

Bill Chadwick, a research assistant at Oregon State University, said the undersea volcano is located in the dark part of the Northeast Pacific and has erupted three times since its discovery in 1998, 2011 and 2015.

Fortunately, for residents of California, Oregon and Washington, the axial seamounts do not explode, so it poses zero risk to any tsunami.

"Mountain Lakes St. Helens Mountains - Crater Lakes - Top of the Mountains - This volcano has more gases, generally explosive. The magma is more viscous," Chadwick said. "The axial direction is more like the volcanoes in Hawaii and Iceland... less gas, the lava is very smooth, so the gas can be emitted without explosion."

The destructive power of explosive eruptions is legendary: when Mount St. Helens erupted in 1980, 57 people died. When the Hunga Tonga-Hunga Ha'apai volcano in the Tonga Islands exploded in 2022 (an event once a century) - the resulting tsunami reached a maximum height of 72 feet, causing damage to the Pacific Ocean and killing at least six people.

In contrast, the Axial Sea Mountain is a volcano that emits lava during the eruption, similar to the type of eruption in Kiravea on the Great Island of Hawaii. As a result, there is no obvious axial explosion in people on land.

This is a completely different story.

William Wilcock, a professor of oceanography at the University of Washington, said the heat from the eruption would rise from the seabed but would not reach the ground.

Chadwick said the outermost layer of the lava flow cools almost immediately and forms the earth's crust, but the interior of the lava flow can melt for a period of time. "In some places... the lava is getting slower and slower, and then all the heat takes a long time to dissipate. Under those thick flows, the microbial pad can grow and almost look like snow on the landscape."

If buried in lava, marine life could die, which could also damage or destroy scientific equipment installed around volcanoes to detect eruptions and earthquakes. But the eruption may not affect marine life, such as whales "whales that are too close" to be plagued by the eruption, Wilcock said.

Likewise, a long-term stimulus 9.0 earthquake is not expected to be triggered in the Cascadia subduction zone. Such an earthquake could create a catastrophic tsunami for the northernmost coastal counties of Washington, Oregon and California. That's because the axial sea and mountain are too far from that major fault.

The Axial Sea Mountain is one of the countless volcanoes. Scientists estimate that 80% of Earth's volcanic production (magma and lava) occurs in the ocean.

The axial sea and mountains aroused strong interest from scientists. Now, it is the best underwater volcano in the world.

Chadwick said the volcano is prolific Eluput, partly because of its location. Not only does it inhabit the ridges, where Juan de Fuca and the Pacific tectonic plates spread to each other - creating a new seabed in the process - but the volcano is also firmly planted above the geological "hotspots" where plume mass overheated magma rises toward the Earth's surface.

For Chadwick and other researchers, frequent eruptions offer tempting opportunities to predict volcanic eruptions weeks to months ahead of time—which is hard to do with other volcanoes. (If scientists get it wrong, there is little chance that anyone will get angry.)

"For many volcanoes around the world, they sit around, sleep for a long time, and then suddenly they become active. But, at least for the time we've been studying it, it's very active," Chadwick said. "If there's no eruption, it's ready for the next one."

Scientists know this because they discovered a pattern.

"During the eruptions, the volcano slowly expands - which means the seafloor rises...and then during the eruptions, when the magma comes out, the volcano will come and the seafloor will fall."

Chadwick said the outbreak “is like getting some air in the balloon. What we see is that every time the eruption is triggered, it expands to a similar level every time.”

Chadwick and scientist Scott Nooner predicted the 2015 eruption of the volcano seven months after realizing that the seabed expanded very quickly and linearly. "This makes it easier for people who infer futures to reach the threshold they have reached before," Chadwick said.

But making predictions since then is more challenging. Chadwick started making forecast windows in 2019, but around that time, inflation started to slow down and by the summer of 2023, “it almost stopped.

But by the end of 2023, the seabed slowly began to expand. Since early 2024, “this has been going at a pretty steady pace.” He and Nooner of the University of North Carolina Wilmington made the latest eruption forecast in July 2024 and posted it on their blog. Their predictions remain the same.

"With inflation, I hope it will explode by the end of this year," Chadwick said.

However, based on seismic data, it is unlikely that volcanoes will erupt quickly. Although scientists have not mastered the prediction of volcanic eruptions for weeks or months in advance, they have used clues such as high frequency of earthquakes to predict eruptions to predict the time of eruptions for minutes to hours.

At this point, “we didn’t see high earthquake velocity before 2015,” Chadwick said. "If it breaks out tomorrow, it won't shock me, but I don't think it's going to be anytime soon in general."

He warned that his predictions are still equivalent to an experiment, although they have become publicly made predictions. "I think that's what it says, not to look back," Chadwick said in a November speech. The forecast began to draw attention after he gave a speech at the American Geophysical Union meeting in December.

On the bright side, he said, “There is no problem alert or wrong problem” because these predictions will not affect people on land.

"Maybe the course could be applied to other more dangerous volcanoes around the world," Chadwick said. But what is now now is the prediction of eruptions of many volcanoes on land "just more complex" without "a pattern as repeatable as we see at sea."

Scientists elsewhere have studied other methods to predict outbreaks. Scientists are beginning to notice the repetitive pattern of rising temperatures in hydrothermal vents in the Eastern Pacific volcano, with three eruptions at the same site over the past three decades. “It kind of worked,” Chadwick said.

Much of luck allowed scientists to photograph eruptions at volcanic sites, called "9 degrees rising 50 minutes in the Eastern Pacific", and this is only the third time that scientists have captured images of active undersea volcanoes.

However, Chadwick suspects that researchers will be lucky enough to video the eruption of the axial sea mountain.

Although the National Science Foundation-funded Ocean Observatory initiative will remind scientists that the program is a regional wired array—a sensor system operated by the University of Washington—to get there in time will be a challenge.

"You have to be in the right position at the right time to catch up with the outbreaks because they don't last very long. The axial direction can last for a week or a month," Chadwick said.

It is then difficult to capture images by taking a boat and a remotely operated vehicle or submarine. Such ships are usually arranged very far ahead, perhaps a year or a half, and are closely arranged.

Chadwick last visited the 2024 volcano and is expected to go out in the summer of 2026. If his prediction is correct, the axial sea and mountain will have already exploded.