Structure of the upper mantle under the Antarctic Plate from surface wave tomography

• Published in: Geophysical Research Letters
• Main Authors: Danesi, Stefania, Morelli, Andrea
• Other Authors: Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Bologna, Bologna, Italia
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU 2001
• Subjects: Antarctic; East Antarctica; Ross Sea; The Antarctic; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2122/15006; https://doi.org/10.1029/2001GL013431

We have analyzed surface wave data for 245 events occurring in Antarctica and surrounding oceans during years 1991-1999. We first apply dispersion analysis to the fundamental mode of Rayleigh waves for periods ranging from 20 to 150 sec. We then invert path-averaged dispersion curves to obtain 2D maps of group velocity for different periods, represented by splines on a grid with 250 km spacing, with considerably more detail than that achieved by global models. We finally use group velocity maps in a nonlinear inversion for the regional 3D υSV structure of the upper mantle. The resulting model shows thick continental roots under East Antarctica, reaching depths below 200 km; low velocities under oceanic ridges, mostly confined to the upper 150 km; and a slow area under the Ross Sea volcanic centres, extending all the way down to 200 km, beyond which our data loose resolving power. Published 4395-4398 1T. Struttura della Terra JCR Journal