In a historic scientific breakthrough, researchers have captured the first recorded detection of a landslide-induced tsunami using satellite data from a ship’s onboard navigation system. This discovery offers new hope for improving early warning systems for coastal communities at risk from such sudden, devastating events.

The study, conducted by scientists from the Cooperative Institute for Research in Environmental Sciences (CIRES) and the University of Colorado Boulder, was recently published in Geophysical Research Letters. It underscores the potential of maritime satellite systems to detect tsunamis not caused by earthquakes—something that current warning systems often fail to catch.

A Tsunami Born from a Landslide

The event occurred on May 8, 2022, near Seward, Alaska, when a landslide sent debris crashing into Resurrection Bay. The collapse generated small tsunami waves—too localized for traditional seismic warning systems to register.

Fortunately, the R/V Sikuliaq, a research vessel docked just 650 meters from the site, had a Global Navigation Satellite System (GNSS) receiver on board. The equipment, installed by Ethan Roth, the ship’s science operations manager and co-author of the study, played a crucial role in capturing the event.

“This is the first time a landslide-triggered tsunami has been detected through satellite data from a ship,” said Anne Sheehan, a CIRES Fellow and professor at CU Boulder. “It shows that, with the right technology on board and some luck in timing, ships can serve as valuable tools for tsunami detection.”

Serendipity and Science

Sheehan happened to be in Alaska at the time, collecting seismometers for another project. During a visit to the R/V Sikuliaq, she learned about the nearby landslide and saw footage of the incident filmed by a crew member. Recognizing the scientific opportunity, her team dove into the ship’s GNSS data to see if it captured the tsunami’s impact.

Adam Manaster, a graduate student in Sheehan’s geophysics lab, led the data analysis with support from the US Geological Survey and the University of Alaska Fairbanks. Using open-source software, they measured minute vertical shifts—accurate to the centimeter—in the ship’s position before, during, and after the tsunami.

By comparing these shifts with tsunami simulations, the team was able to confirm that the R/V Sikuliaq had indeed recorded the vertical motion of waves generated by the landslide.

A New Tool for Coastal Safety

“This study shows that ships can help determine when and where landslide tsunamis occur,” said Manaster. “With fast data processing, we could issue real-time alerts to help people evacuate in time.”

Landslide-triggered tsunamis pose a unique danger because they often occur without the earthquake signals traditional systems rely on. This new approach—detecting them through GNSS-equipped ships—offers a valuable supplement to existing warning technologies.

Broader Implications

The research builds on previous CIRES work demonstrating that commercial ships’ GPS systems can play a role in tsunami detection. However, making this method a widespread reality would require cooperation from the shipping industry, including access to onboard navigation data.

“The science proves this method works,” Sheehan emphasized. “Now we need to explore how we can implement it at scale to help protect vulnerable coastal areas.”

As climate change increases the risk of landslides and extreme weather events, tools like ship-based satellite monitoring may become essential for safeguarding lives and infrastructure along coastlines worldwide.