Combined use of the GGSFT data base and on board marine collected data to model the Moho beneath the Powell Basin, Antarctica

• Main Authors: Chávez Segura, René, Flores Márquez, Elsa Leticia, Suriñach Cornet, Emma, Galindo Zaldívar, Jesús, Rodríguez Fernández, José, Maldonado, Andrés
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidad de Barcelona; Instituto de Ciencias de la Tierra Jaume Almera 2007
• Subjects: Gravity; Inverse theory; Antartic Peninsula; Powell Basin; Marine geophysics; Antarctic; Antarctic Peninsula; South Scotia Ridge; The Antarctic; Antarc*; Antarctica; antartic*
• Online Access: http://hdl.handle.net/10481/32075

The Powell Basin is a small oceanic basin located at the NE end of the Antarctic Peninsula developed during the Early Miocene and mostly surrounded by the continental crusts of the South Orkney Microcontinent, South Scotia Ridge and Antarctic Peninsula margins. Gravity data from the SCAN 97 cruise obtained with the R/V Hespérides and data from the Global Gravity Grid and Sea Floor Topography (GGSFT) database (Sandwell and Smith, 1997) are used to determine the 3D geometry of the crustal-mantle interface (CMI) by numerical inversion methods. Water layer contribution and sedimentary effects were eliminated from the Free Air anomaly to obtain the total anomaly. Sedimentary effects were obtained from the analysis of existing and new SCAN 97 multichannel seismic profiles (MCS). The regional anomaly was obtained after spectral and filtering processes. The smooth 3D geometry of the crustal mantle interface obtained after inversion of the regional anomaly shows an increase in the thickness of the crust towards the continental margins and a NW-SE oriented axis of symmetry coinciding with the position of an older oceanic spreading axis. This interface shows a moderate uplift towards the western part and depicts two main uplifts to the northern and eastern sectors. We are thankful to the Hespérides Working Group who provided some original data. CGL2004-05646/ANT and University of Barcelona and DGIA-UNAM Interchange program financed this study. The CONACyT, Mexico, also supported Dr. E. L. Flores-Márquez and R.E. Chávez stays at the Universidad de Barcelona.