Seismologists Trace 250-Km Quake Line to Yakutat Slab Edge, Linking It to 2002 Denali Shock
Updated
Updated · ScienceAlert · Jul 1
Seismologists Trace 250-Km Quake Line to Yakutat Slab Edge, Linking It to 2002 Denali Shock
1 articles · Updated · ScienceAlert · Jul 1
Summary
A 250-kilometer chain of previously undetected small earthquakes has revealed the precise edge of the subducted Yakutat microplate beneath central Alaska, offering a likely source zone for the 2002 magnitude 7.9 Denali earthquake.
Machine-learning analysis of seismic records and inter-earthquake noise exposed the 'razor-sharp' northwest-to-southeast line, which traditional methods had not resolved in such detail.
The mapping shows the Yakutat slab extends farther beneath the North American plate than previously known and reaches below the Denali fault, where researchers say changing slab shape reflects a shift in stress.
That geometry suggests plate collision and subduction helped load stress into the Denali fault, while also supporting theories that the slab influenced relatively young volcanic fields in south-central Alaska.