Scientists from the Norwegian University of Science and Technology have unveiled a method for tracking silently moving underwater and surface objects by using existing fiber-optic cables to measure water displacement.

The scientists behind the novel detection approach, which was designed to detect whales even when they aren’t vocalizing, also demonstrated the method’s ability to track surface ships and potentially underwater vessels, such as submarines, that traditionally rely on silence for stealth.

Tracking Silently Moving Whales and Other Objects

In the research team’s study, the authors explain that it is already possible to record and reconstruct marine mammal vocalizations, including those of whales, using seabed fiber-optic cables. They note that the current method, called distributed acoustic sensing (DAS), allows scientists to passively monitor whale behavior, “enabling both the detection of vocalizations and the simultaneous tracking of multiple individuals.”

However, they add, although this data can prove valuable in tracking these increasingly endangered animals, “it has not been possible to track marine mammals when they are silent.”

“A fundamental limitation of passive acoustic monitoring is that most methods rely on acoustic data, which is only available when whales vocalize,” the study authors explain, adding that this limitation “clearly demonstrates the need for new sensing methods that can detect silent whales.”

Although the researchers propose several methods, including combining DAS data with satellite and observational data to paint a more complete picture, they also note a “second path” that involves exploring current datasets to discover new, valuable acoustic signatures even when the animals are silent.

Detecting Hydrodynamic Pressure Changes Caused by Ships and Animals

When exploring new ways to interpret DAS data collected by seabed fiber-optic cables, the team explained how low-frequency strain variations may arise from “a range of physical mechanisms.” These include hydrodynamic processes “associated with moving objects.”

For example, the authors explain, when a ship moves across the ocean surface, it pushes water ahead of it and draws water along in its wake. This motion through the water medium generates a strain on the surrounding water described as a hydrodynamic pressure field. According to the team, this motion-induced pressure field  “extends downward through the water column.”

“The displacement of water generated by moving whales and ships induces a moving hydrodynamic pressure field that extends through the water column, dynamically loading and unloading the seafloor,” they explain.

Changes in this pressure field caused by moving objects cause sediments on the ocean floor to deform laterally and vertically. In areas of the seafloor with fiberoptic cables buried underneath, the DAS system records this “lateral deformation” of the sediments, which “translates into strain that can be observed in the DAS data.”

“This means that no acoustic signal is involved, and we can ‘listen’ to silent whales,” they write.

Tests Demonstrate Tracking Surface Ships and Submerged Whales

To calibrate their approach, the team used surface ships as “proxies” in a series of field experiments. According to their study, the four interrogator units (IU) were installed “during the DAS experiment on Svalbard in 2022.” Then, another unit was installed in Longyearbyen in March 2025. Although the study focuses on the newer IUs, the team notes that all the experimental data “was used to analyze how coupling affects the detectability of hydrodynamic pressure field signatures and how the signal characteristics change with increasing source-receiver distance.”

In those experiments, the team investigated four ships of different sizes. Notably, all ships were observed at a depth of 70 to 80 meters and were traveling at roughly the same speed. Critically, ship size, speed, and route data can be verified externally, providing a check on the study’s results.

“Ships are observed in the DAS data year-round, and the AIS is available to confirm which ship is sailing above the fiber and at what time,” they explain.

As expected, they found that the DAS signal amplitude “scales with the size of the ship.” For example, the smallest ship they observed barely registered above the background noise, making it the hardest to track. Conversely, the largest vessel tracked by the team, an icebreaker, left the clearest signal.

The researchers also demonstrated the ability to observe hydrodynamic pressure and velocity signals from a cruise ship at a water depth of 413 m, “and up to 550 m from the fiber cable.” However, when the team searched for whales, the range was much more limited.

“The smaller blue whales can be observed when diving within 40 m of the fiber-optical cable,” they explain.

During a dedicated test segment, the team monitored what they interpreted as several silently moving whales traversing through the detection zone. Although they were unable to independently confirm they were whales in the same way they could confirm the ships, the team notes that “multiple lines of analysis support the interpretation that whales are responsible for the observed signals.”

The team also notes that AIS data confirmed that no acoustic ship signatures were present “in the time window studied.” They add that this result “reduces the likelihood that the observed low-frequency signals originate from vessels.”

The Signal Amplitude Decreases with Increasing Distance From the Fiber

When discussing the implications of their findings, the team said their data shows that the observed low-frequency response captured by the fiber-optic cables “is consistent with translating hydrodynamic pressure fields generated by the displacement of water by moving ships and other large bodies such as whales.”

“This sensing method enables an approach to monitoring one of the world’s most endangered species,” they explain, adding that it is even more effective at detecting submerged objects than at detecting surface ships.

“A fully submerged object generates a more symmetric pressure field, while a surface-bound ship produces a truncated field due to the air–water interface, which limits the downward extent of the pressure field,” the study authors write.

When discussing the limitations of their innovative, silent, object-tracking approach, the team notes that it is only effective for tracking smaller ships and whales at close range.

“Kvitungen is the smallest ship investigated in this work and is barely observed above the noise floor for a water depth of ∼75 m,” they write. “Blue whales are even smaller and are unlikely to be detected at distances greater than approximately 30 to 40 m from the fiber.”

The team also notes that although larger ships generate stronger signals than smaller ones, “the signal amplitude decreases with increasing distance from the fiber.”

Other limitations involved data returns suggesting whales that were either “abnormally long or surprisingly small.” The team said this seemingly impossible result “underlines that our simple model needs further development to obtain more precise results.”

The study “Detecting silent whales using seabed fiber-optic cables” was published in the Proceedings of the National Academy of Sciences (PNAS). 

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

An international team of geophysicists examining the Southern Indian Ocean floor witnessed a section greater than two meters split apart, releasing millions of cubic meters of stored-up magma within just a few days.

Jean-Yves Royer, a marine geophysicist at the French National Centre for Scientific Research (CNRS) in Brest and a co-author of the study detailing the team’s serendipitous discovery, said witnessing the ocean floor splitting apart in real time was “a major surprise,” while the team hailed the scientific value of finally witnessing these processes up close.

Scientists Have Never Witnessed The Ocean Floor Splitting Apart in Real Time

Because the ocean floor is dynamic, the movement of tectonic plates pulling the existing crust away from mid-oceanic ridges allows magma to well up to the surface. When it dries, this material solidifies, adding to the existing crust. While scientists have understood this process for decades, no one has ever witnessed the phenomenon directly. This absence has left a gap in scientific knowledge that, as study co-author Isobel Yeo, a geoscientist at the National Oceanography Center in Southampton, UK, notes, persists to this day.

“We still know remarkably little about the frequency, magnitude, and dynamics of the eruptions and tectonic processes that build them”, the researcher explained

To try to fill that gap, the team focused its research on a section of the seafloor called the Southeast Indian Ridge, which runs east to west across the Indian Ocean. Due to its location, the ridge separates two tectonic plates, the Antarctic and the Australian.

The team notes that these two plates, which contain Antarctica and Oceania and the surrounding oceanic crust, are continuously moving in opposite directions by roughly six centimeters each year. Although both plates are exerting stress on the ridge, the team said the northward movement of the Australian plate accounts for most of this annual expansion.

The motion dynamics can also change by location. For example, one section of the Australian plate may stay stationary for a period and then suddenly experience a large surge in motion. These sudden events are accompanied by earthquakes. 

Ocean Floor Movement in Real Time

In hopes of catching the ocean floor splitting in real time, Royer and colleagues ventured to the Southeastern Indian Ridge in February 2024. Once on site, the team deployed three categories of sensors at several different locations along a 100-kilometer stretch of the ridge. The sensor array included five hydrophones that detect underwater sound, including the telltale sonic waves produced by earthquakes. The team also deployed 15 battery-powered acoustic beacons designed to emit and detect sounds at selected locations along the ridge.

Because the acoustic beacons can produce and receive sounds, the team programmed them to exchange audio signals every four hours. This regular exchange allowed the team to measure the time between sound and response, which they used to determine the distance between the two beacons at four-hour intervals.

After the sensors were all in place, the team’s efforts finally paid off. According to the study, the carefully placed hydrophones began to detect seismic tremors on the ocean floor. These signals were followed by several days of acoustic beacon returns, indicating some of the stations had moved. When the team calculated the time between beacon signals, they determined that some sections of the ocean floor had moved by “at least” two meters as they were pulled away from the ridge.

The team also found evidence that the ocean floor was splitting apart in real time, altering the ocean floor’s depth. According to a reading from a single pressure sensor, the depth change caused by the event was “substantial.”

a rare direct view of these processes in action

In the study’s conclusion, the research team estimates that 160 million cubic meters of lava rose between the split ocean floor and spilled onto the seafloor. They also suggested that the magma explosion emptied a reservoir that had accumulated along the ridge, which caused portions of the floor to “subside.”

Royer said the team was only expecting to find a vertical displacement of “a few centimeters.” Instead, he notes, “we measured 4.2 meters.” The team said this large amount of change suggests that three to six decades’ worth of stress from the northward movement of the Australian tectonic plate was released during the ocean-floor-splitting event.

When discussing the significance of witnessing the ocean floor splitting apart in real time for the first time, Yeo said their study “provides a rare direct view of these processes in action.”

The study “Anatomy of a seafloor spreading event captured by in situ seismogeodesy” was published in Nature.

 Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

Scientists from Arizona State University have performed computer simulations suggesting viable methods for controlling the weather by ‘nudging” systems in their development stages with proven technologies to mitigate or even completely avoid the damage from extreme weather events.

Although the new approach, which the team termed “Weather Jiu-Jitsu,” hasn’t been tested in real-world conditions, the researchers behind the new perspective paper outlining the process said it could help humans better prepare for severe weather systems by finding ways to live with nature rather than reacting to it.

Controlling the Weather Could Mitigate Property Damage and Loss of Life

When detailing their approach, ASU researcher Qin Huang and colleagues highlight the historical damage caused by extreme weather events, including floods, heat waves, droughts, and ‘freezes.’ In addition to the loss of life, estimates suggest that climate extremes caused $417 billion in damage in 2024 alone.

The paper’s authors also note that such extreme weather events “are increasing in frequency and intensity,” a trend research suggests is strongly driven by rising global temperatures. Although there have been some efforts to mitigate the effects of extreme weather, the paper’s authors write that increasing populations and continued climate change “heighten exposure to risks that conventional infrastructure cannot fully address.”

“The growing impact of weather extremes on society highlights that traditional approaches such as dams, levees, and insurance alone may not be sufficient to address the widespread consequences of these hazards,” the authors write.

To explore alternatives, the team wondered if small adjustments to burgeoning weather systems could redirect their paths or lessen their severity. In some ways, it’s like redirecting an incoming meteor to miss the Earth or hit it at a more oblique angle to lessen the impact.

“Imagine harnessing the power of nature to help steer hurricanes away from land, redirect atmospheric rivers to spread their rain safely and evenly, or defuse extreme weather patterns like heatwaves, freezes, or prolonged droughts before they take hold,” Huang and colleagues write. “It’s a vision where we partner with Earth’s own forces to create resilience, rather than reacting to disasters. We call it Weather Jiu-Jitsu.”

‘Nudging’ Weather System Trajectories with Weather Jiu-Jitsu

When detailing how the process would work, the team explained that Weather Jiu-Jitsu takes advantage of the “chaotic sensitivity of mid-latitude atmospheric dynamics to redirect destructive weather trajectories through small, precisely timed perturbations,” using forecasting models that project system paths and intensities.

“Our thesis is that Weather Jiu-Jitsu, i.e., adaptive chaos control applied to mid-latitude atmospheric dynamics, may provide a 21st century approach to managing a range of extreme weather events by nudging the system trajectories,” they explain.

Due to the challenges and risks of testing weather-control methods in real-world conditions, the researchers developed proof-of-concept computer simulations. Critically, their approach used established models of atmospheric circulation and a large-scale artificial intelligence “deep-learning Earth system” model, Aurora, designed to predict weather at high resolution.

According to the team’s research, carefully timed seeding of clouds could have major impacts on a storm’s path and intensity, noting that “nudges applied days before peak impact can shift a hurricane track to avoid landfall on a major city, weaken the peak intensity of a blocking-driven cold extreme, and reduce atmospheric river moisture transport under favorable upstream conditions.”

When testing their weather control approach on historically extreme climate events, the results were significant. For example, the team found that small, carefully timed cloud seeding operations applied in the critical days before the peak of an extreme weather event “could have shifted the track of the 2012 Hurricane Sandy by about 300 miles to miss New York City.”

The model also indicated that a similar approach could have raised the lowest temperature extremes experienced during the 2021 Texas freeze “by about 18 degrees Fahrenheit.” Similarly, the model revealed that the approach could have reduced the damaging precipitation levels associated with the 2022 atmospheric river that caused flooding in California by about 5%.

“By leveraging the atmosphere’s inherent sensitivity, Weather Jiu-Jitsu seeks not to overpower nature, but to collaborate with it: nudging storm tracks, influencing jet stream meanders, and possibly mitigating compound extremes before they fully develop,” the authors explain.

Revolutionizing the Risk from Extreme Climate Events

When discussing the potential impacts of controlling the weather before serious damage can occur, the study authors noted that it would be “transformative” for the planet. They also noted that controlling the weather could offer an outsized benefit to the most vulnerable people “who do not have recourse to other protections from weather extremes.”

Still, they add that demonstrating the real-world benefits of their approach to controlling the weather while accounting for “natural variability” will require evidence of tangible outcomes. The suggestion is that these metrics would include “reductions in peak precipitation intensity, flood inundation extent, and insured economic losses.”

To achieve this goal, Huang and colleagues recommended a three-stage approach. In the near term, they suggested starting with “controlled deep-learning perturbation experiments” for historical extreme events like floods and droughts, and air them with an “observational system design.” In the medium term, Huang and colleagues suggested implementing “scaled regional pilot studies” and developing a “governance framework development with WMO and UNEP.” The final proposed phase involved limited operational pilot experiments in select locations “under formal international oversight with systematic outcome monitoring.”

“We outline an argument that control over catastrophic weather extremes is imperative to reduce exposure to catastrophic events that are not mitigated by traditional physical, financial, or social infrastructure, and explore conditions under which this may be feasible,” the authors conclude. “If such an approach were successful, it could revolutionize hydroclimatic risk mitigation.”

The study “Weather Jiu-Jitsu: Prospects for atmospheric nudging to defuse the impact of catastrophic weather extremes” was published in PLOS Water.

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.