Regional Structure of the Antarctic Peninsula Derived from ERS-1 SAR Mosaic: A Study of Upper/Lower Plate Interactions During Subduction of the Antarctic/Aluk Ridge Crest

点击翻译按钮获取中文摘要

Abstract This award supports a project to use synthetic aperture radar (SAR) data from the European ERS-1 satellite for a structural analysis of the Antarctic Peninsula. This project constitutes a demonstration of the use of SAR data for geological and geophysical investigations in largely ice covered regions. The Cenozoic tectonic evolution of the Antarctic Peninsula involves a history of geometrically simple orthogonal plate subduction, with successive collision of fracture zone-bounded segments of the Antarctic-Aluk ridge crest from south to north along the convergent margin. It has been proposed that the subducted fracture zones are reflected in geological and structural segmentation of the Antarctic Peninsula and, therefore, a direct mechanical interaction between the upper and lower plates along the subducting margin is suggested. Structural mapping from a synoptic ERS-1 SAR mosaic of the entire Antarctic Peninsula should document the regional continuity of any fracture zones into the continental crust and any systematic changes in structure within the peninsula that may be linked these fracture zones. The goal is to systematically evaluate the impact of subducting fracture zones on the upper plate along the convergent margin. The Antarctic Peninsula provides an unrivaled opportunity for such a study because the ocean floor record is well documented, Oground truthO exists from high-quality geologic mapping and field structural data, and the convergent margin represents the least complex scenario of fracture zone/trench interaction. The results of this study can provide a model for other convergent margins worldwide where the tectonics are more complicated. Furthermore, this approach, using an ERS-1 SAR mosaic, will serve as a prototype for SAR-based structural mapping in ice-covered terrain that should prove useful when RADARSAT data becomes available.