Study shows low-angle subduction zones can generate giant earthquakes contrary to classic theory

A research team headed by Professor Satoshi Ide of the University of Tokyo has shown that the long‑standing theory of earthquake generation fails in regions where tectonic plates subduct at shallow angles. Published in *Science Advances*, the study demonstrates that the mechanics of fault rupture differ markedly when the downgoing plate dips less steeply, allowing large earthquakes to develop in places previously thought to be too stable for such events.

The findings clarify why great seismic events have occurred in low‑angle subduction zones and provide a theoretical framework that could broaden the scope of monitoring programs. By identifying previously overlooked structural features that can accommodate significant strain, the research offers a new basis for targeting future observational and risk‑assessment efforts in these vulnerable regions.