See NASA’s GUARDIAN Catch a Tsunami
A new data visualization illustrates how an experimental NASA technology can provide extra time for communities facing a tsunami. Called GUARDIAN (GNSS Upper Atmospheric Real-time Disaster Information and Alert Network), the software detects slight distortions in satellite navigation signals to spot moving dangers.
The animation presents a real-life case study: last summer’s massive Kamchatka earthquake and the tsunami it sent across the Pacific and toward Hawaii at more than 500 mph (805 km/h).
The visualization shows the magnitude 8.8 earthquake (in purple) that struck the Russian coast on July 29, 2025, triggering the tsunami. The red, orange, yellow and green loops represent real-time readings from ground stations that track GPS and other satellite navigation signals. The disturbances were spotted by GUARDIAN’s artificial intelligence-based detection algorithms just eight minutes after the earthquake.
Over the next few hours, signs of the tsunami were picked up by GUARDIAN across the Pacific Ocean, almost in real time. The system reported an incoming wave off the coast of Kauai approximately 32 minutes before it made landfall and was detected by tide gauges (shown in blue).
The results highlight GUARDIAN’s potential to augment existing early warning systems, said Camille Martire, one of its developers at NASA’s Jet Propulsion Laboratory in Southern California.
Currently, determining whether an earthquake generated a tsunami remains a challenge. Forecasters rely on seismic data and computer simulations to make their best predictions, then wait for pressure sensors attached to the ocean floor to confirm a wave has passed. These sensors work well but are expensive and poorly distributed. Gaps remain in coverage. And in these intervals, the warning time disappears.
The GUARDIAN approach is complementary and cost-effective because it monitors existing data from GPS and other constellations that make up the global navigation satellite system. Access is also free, but is currently best suited to analysts trained to interpret its findings.
All day, every day, geopositioning constellations transmit radio signals to ground stations around the world. On the ground, the data is refined to sub-decimeter positioning accuracy (less than 10 centimeters) by JPL’s Global Differential GPS system. However, before the signals arrive, they must pass through an electrically charged skin of plasma called the ionosphere.
Solar storms and other space weather can cause electrical damage in the ionosphere, just like events on Earth. Tsunamis and earthquakes, by moving large amounts of air across the Earth’s surface, release pressure waves that can slightly disrupt radio signals coming from satellites. Although systems are in place to correct this “noise”, GUARDIAN considers it a useful signal.
Currently, GUARDIAN is scouring data from more than 350 GNSS ground stations around the Pacific Ring of Fire, a hotbed of the ocean’s deadliest waves. And the system is not limited to tsunamis. Earthquakes, volcanic eruptions, missile tests, spacecraft reentries, meteoroid landings – anything that produces a big rumble on Earth is potentially fair game. Although the Kamchatka event did not cause significant damage to people or property, it showed that the next time a disaster strikes, NASA science could give communities a few extra minutes to act.
GUARDIAN is developed at JPL by the GDGPS project, partially supported by NASA’s Space Geodesy Project.
To learn more, visit: https://guardian.jpl.nasa.gov/
Media contacts
Andrew Wang / Andrew Bon
Jet Propulsion Laboratory, Pasadena, California.
626-379-6874 / 818-393-2433
andrew.wang@jpl.nasa.gov / andrew.c.good@jpl.nasa.gov
Written by Sally Younger
2026-017
