What deep sea mud is revealing about giant earthquakes along the Pacific Coast

Phys.org • January 19, 2026 • general

Key Points:

Researchers have developed a new method to link marine turbidite layers—mud and sand deposits from underwater landslides—to specific landslides, improving the accuracy of earthquake history reconstructions.
Using autonomous underwater drones and tethered robots, the team created high-definition seafloor maps off Crescent City, California, and collected mud samples from both turbidites and their source hills for radiocarbon dating.
The matching ages of mud from the hills and the seafloor suggest that fresh mud is pushed up from beneath due to tectonic activity at a subduction zone, meaning these underwater landslides are triggered by earthquakes rather than storms.
This breakthrough allows scientists to confidently associate deep-ocean turbidite deposits with