Hidden 'Razor-Sharp' Earthquake Line Reveals Alaska's Secret Microplate

Scientists have uncovered a 250-kilometer-long, 'razor-sharp' line of thousands of previously hidden tiny earthquakes beneath Alaska, a discovery that clearly outlines a secret, actively subducting microplate. This finding, published on June 4, 2026, in The Seismic Record, finally maps the precise edge of the Yakutat microplate as it dives under the larger North American Plate, giving us a clearer picture of Alaska's complex underground movements. This newly identified seismic line shows the Yakutat microplate, a thick piece of oceanic crust, is currently caught in a 'tectonic traffic jam' with the Pacific Plate, pushing hard against the North American Plate. This intense collision is believed to shape the pattern of earthquakes and volcanoes across south-central Alaska, even potentially influencing major past events like the powerful magnitude 7.9 Denali earthquake in 2002. The way this microplate is moving, shallowly and directly without a typical 'mantle wedge' in some areas, helps explain the unique geological features of the Alaska Range and the Denali Fault. Looking ahead, researchers plan to use these new insights to study older earthquake data, even before 2018, to understand how this microplate has behaved over time. Pinpointing the exact boundaries of the Yakutat microplate and its interaction with the Denali Fault will be crucial for improving our understanding of seismic hazards and volcanic activity in a region known for its powerful quakes. This clearer map of underground forces could change how we prepare for future geological events.