Kinematics and segmentation of the South Shetland Islands- Bransfield basin system, northern Antarctic Peninsula


New GPS measurements demonstrate tectonic segmentation of the South Shetland Islands platform, regarded as a microplate separating the Antarctic Peninsula from the oceanic portion of the Antarctic plate. King George, Greenwich, and Livingston islands on the central and largest segment are separating from the Antarctic Peninsula at 7-9 mm/a, moving NNW, roughly perpendicular to the continental margin. Smith and Low islands on the small southwestern segment are moving in the same direction, but at 2.2-3.0 mm/a. The Elephant Island subgroup in the northeast moves at ∼7 mm/a relative to the Peninsula, like the central group, but toward the WNW. This implies that it is presently coupled to the Scotia plate on the northern side of the South Scotia Ridge transform boundary; thus the uplift of these northeasternmost islands may be caused by Scotia-Antarctic plate convergence rather than by subduction of thickened oceanic crust. Copyright 2008 by the American Geophysical Union.

Publication Title

Geochemistry, Geophysics, Geosystems