ABSTRACT
The Arabian plate is potentially being pulled by subducting lithosphere beneath Eurasia, while also being weakened internally by processes associated with volcanism in the western harrats and uplifting due to buoyancy of the underlying hot mantle. Mantle flow may also be imposing tractional stresses beneath the Arabian lithosphere. Considering these effects, it is surprising that there is only modest deformation of Arabia revealed by GPS measurements, seismicity and faults suggested to have been active in the Quaternary. We review these deformation data along with published data on orientations of horizontal compressive stresses from boreholes. Maximum stresses (S H ) are mostly oriented WSW-ENE near the Arabian Gulf and around it. Along the Red Sea coast, S H suggested by earthquake focal mechanisms and dyke intrusions appears largely to be oriented NW-SE, parallel to the coast. In south Arabia, however, focal mechanisms and borehole breakouts suggest that S H is aligned NNE-SSW. Vents on southern Red Sea volcanic islands are also aligned ~ NNE-SSW, suggesting that this direction of S H continues into the rift. These observations can be largely explained by spatially varied resistance to the subduction of Arabia beneath Eurasia and by ridge push stresses originating from the subaerial Afar spreading centres.
