Blanco Fracture Zone
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The Blanco Fracture Zone or Blanco Fault Zone (BFZ) is a transform fault zone off the coast of the Pacific Northwest of the United States which runs between the Gorda Ridge to the south and the Juan de Fuca Ridge to the north. The principal feature of the Blanco zone is the Blanco Ridge [1], a right lateral-moving fault which also incorporates some compression, thus accounting for the uplift expressed in the ridge. The ridge is not an oceanic spreading center, despite its name, whereas the Juan de Fuca and Gorda Ridges to which it is connected are. Similarly confusing, the Blanco Fracture Zone is not technically a true fracture zone, but a transform fault zone.
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[edit] Seismic Activity
In March and April of 2008, a series or "swarm" of moderate earthquakes occurred both near and within the Blanco zone. The swarm began on March 30 when over 600 measurable tremors begain occurring north of the zone within the Juan de Fuca Plate. [2] On April 22, activity moved to the Blanco fault zone itself, near its junction with the Gorda Ridge.[3]
