Queen Charlotte triple junction

The three plate boundaries which intersect here are the Queen Charlotte Fault, the northern Cascadia subduction zone, and the Explorer Ridge.

First, at approximately 40 Ma the relative plate motions switched from orthogonal convergence to right-lateral strike slip.

Using the locations of these epicentres it is possible to map the Pacific plate boundary along the Dellwood valley where the concentrations of events occur.

[4] The Explorer ridge has been migrating since 5 Ma to the west at a rapid pace(~22 mm/yr), while the Juan de Fuca plate has remained stable.

[2] A similar process to this is taking place in the Rivera triple junction where small ephemeral plates were also formed.

[3] To the southeast the heat flow is reduced through cooling by the subducting plate, and increased to the northwest through crustal extension.