The experimental system, known as GUARDIAN (GNSS Upper Atmospheric Real-time Disaster Information and Alert Network), tracked the atmospheric signature of a tsunami generated by a magnitude 8.8 quake on 29 July. While the waves caused limited damage, scientists said the event highlighted the potential of GUARDIAN to transform early warning systems across the Pacific.
Developed at NASA’s Jet Propulsion Laboratory (JPL) in California, GUARDIAN analyses signals from global positioning system and other satellite networks to detect subtle changes in the upper atmosphere caused by a tsunami’s movement. These distortions can be picked up globally in near real time.
“Those extra minutes of knowing something is coming could make a real difference when it comes to warning communities in the path,” JPL scientist Dr Siddharth Krishnamoorthy said.
The system issued alerts to subscribed tsunami experts within 20 minutes of the earthquake and confirmed signs of the approaching tsunami 30 to 40 minutes before it reached Hawaii and other Pacific locations. In the best scenarios, GUARDIAN could give coastal communities more than an hour’s notice.
Traditional tsunami forecasts rely on seismic data and a sparse network of deep-ocean pressure sensors to confirm wave size and speed. GUARDIAN does not replace those tools but adds a new layer of coverage, especially in areas without seabed instruments.
“NASA’s GUARDIAN can help fill the gaps,” said Christopher Moore, director of the US National Oceanic and Atmospheric Administration’s Center for Tsunami Research. “It provides one more valuable data point that can help us decide whether to issue an evacuation order.”
The technology exploits the physics of tsunamis. When vast areas of ocean rise and fall together, the displaced air sends pressure waves upwards into the ionosphere, where they slightly distort satellite radio signals. GUARDIAN scans data from more than 350 ground stations worldwide to pick up those disturbances.
The Kamchatka quake came just 24 hours after the team activated two major upgrades: an artificial intelligence system to scan incoming signals and a prototype messaging service to push alerts to experts. Both were put straight to the test.
Bill Fry, who chairs the United Nations’ Pacific tsunami early warning working group, described GUARDIAN as part of a technological “paradigm shift”.
“By directly observing ocean dynamics from space, GUARDIAN is exactly the kind of capability we’ve been looking for to underpin next-generation forecasting,” he said.
Australian experts also see promise. Adrienne Moseley, co-director of the Joint Australian Tsunami Warning Centre, said the technology could be a game changer for regional cooperation.
“Tsunamis don’t respect national boundaries,” she said. “Having open access to this kind of data across the region will strengthen everyone’s ability to assess threats and act quickly.”
While no single system can prevent a tsunami from reaching shore, researchers say GUARDIAN’s successful trial during one of the strongest earthquakes on record shows it could play a vital role in saving lives in the decades to come.