Queen Charlotte Fault

[5] The entire approximately 900 km offshore length has ruptured in seven greater than magnitude 7 events during the last century, making the cumulative historical seismic moment release higher than any other modern transform plate boundary system.

The junction of the Queen Charlotte, Fairweather, and Transition faults is located at the southeastern tip of the Yakutat block, an oceanic plateau and microplate.

[5] There are various mechanisms proposed to accommodate oblique convergence along the QCF, this include underthrusting and strain partitioning,[2] crustal thickening,[10] and distributed shear.

[18] This hypothesis is also supported by the morphology of the Queen Charlotte Terrace, an approximately 30 km-wide deformed accretionary prism-like complex west of the main QCF trace.

[19] Several recent studies based on seismicity, GPS observations of coseismic and postseismic deformation, and thermal modeling support the presence of a shallow plate boundary thrust.

The Queen Charlotte Terrace widens and deepens, forming a series of oblique ridges and basins west of the QCF main trace.

[8] In the northern segment, which bore the epicenter of the strike-slip 2013 Craig earthquake, bathymetric data suggests that the ridge-basin complex gives way to simpler fault morphology.

[5] The same location also marks earthquake rupture boundaries between the 2013 Craig event[25] and the 1972 M7.6 Sitka event,[26][27] as well as the inferred intersection of the Chatham Strait Fault and the Aja Fracture Zone (FZ) with the Queen Charlotte Fault; the Aja FZ also marks an approximately 3 million year contrast in Pacific plate crustal age.

[2] Accommodation of strike-slip plate motion along a narrow deformation zone is consistent with focal mechanisms determined for the Craig event and its aftershocks.