Juan de Fuca back

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Schematic map of the plate configuration and plate boundaries in the Pacific Northwest of North America (north is top left).

The Juan de Fuca Ridge is a mid- ocean ridge about 500 kilometers long near the northeastern edge of the Pacific off Vancouver Island and the coast of the US states of Washington and Oregon . It forms the central part of a ridge transform fault system that separates the Pacific Plate in the west from three small plates , the Explorer Plate , the Juan de Fuca Plate and the Gorda Plate , in the east. In the north, the Juan de Fuca ridge meets the Sovanco fracture zone , via which it is connected to the Explorer ridge . In the south it is bounded by the Blanco fracture zone, through which it is connected to the Gorda ridge . This system is considered to be part of the East Pacific Ridge , which has become increasingly shorter and more isolated as a result of the collision of this ridge with the North American Continental Bloc for about 30 million years and North America's continued western drift.

The back and plate of the same name are named after the Juan de Fuca Strait south of Vancouver Island. The Juan de Fuca Ridge was first scientifically mentioned and named in 1965 by the Canadian geologist John Tuzo Wilson .

The spreading of the ocean floor along the ridge is accompanied by intense submarine volcanism . The most important volcano is the deep-sea mountain Axial Seamount , which lies at the intersection of the Juan de Fuca ridge with the Cobb seamount chain. It towers over the ocean floor by 1,100 m and thus rises to 1,400 m below sea level. Its outbreaks in 1998 and 2011 could be observed by measuring devices. Based on these observations, the eruption of April 24, 2015, was the first time that a volcanic eruption could be precisely predicted.

The spreading rate on the Juan de Fuca ridge is around 5 cm per year.

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  1. ↑ Patricia A. McCrory, Douglas S. Wilson, Richard G. Stanley: Continuing evolution of the Pacific-Juan de Fuca-North America slab window system - A trench-ridge-transform example from the Pacific Rim. Tectonophysics. Vol. 464, No. 1-4, 2009, pp. 30-42, doi : 10.1016 / j.tecto.2008.01.018 .
  2. ^ John Tuzo Wilson: Transform faults, oceanic ridges, and magnetic anomalies southwest of Vancouver Island. Science. Vol. 150, No. 3695, 1965, pp. 482–485, doi : 10.1126 / science.150.3695.482 (alternatively: JSTOR 1716955 , UCSC )
  3. ↑ Axial Seamount. Pacific Marine Environmental Laboratory (PMEL), National Oceanic and Atmospheric Administration (NOAA) (English).
  4. ↑ National Geographic: Underwater Volcano Offers Rare Look at Eruption in Real Time , December 15, 2016
  5. ^ Charles DeMets, Richard G. Gordon, Donald F. Argus: Geologically current plate motions. Geophysical Journal International. Vol. 181, No. 1, pp. 1–80, doi : 10.1111 / j.1365-246X.2009.04491.x ( Open Access ), p. 55.