A Review of the Structure of Mid-Ocean Ridge Systems with Applications to the Tectonic History of the Northeast Pacific

The physical properties of mid-ocean ridge systems are determined primarily through the use of thermal models. It was found that a leaky transform fault could be described by using a similar method. The stability of these ridge systems depends on the stress field that is acting upon them. Mid-ocean ridges can undergo substantial deformation which can be brought about by changes in the stress field. Such an effect is expected to be greater as a ridge gets in close proximity of a trench. In the case of the northeast Pacific, the model of Atwater (1970) for the tectonic history of the region is not compatible with the observed magnetic data, under the assumption that major changes in the stress field should be mirrored in the magnetic anomalies. A newer model in which the East Pacific Rise reaches the trench at 24 myBP is presented here. Such a model requires that the trench remain for another 4 m.y. before converting into a transform fault