Friday, 31 August 2007
5.PS-144
Volcanic Deformation Models for Deception Island (South Shetland Islands, Antarctica)
Alberto Fernandez-Ros, Manuel Berrocoso, and M. Eva Ramírez. Astronomy, Geodesy and Cartography Laboratory, Department of Mathematics, Universidad de Cádiz, Facultad de Ciencias, Campus de Puerto Real, s/n, 11510, Puerto Real (Cádiz), Spain
GPS observations from a Deception Island Volcano geodetic network (South Shetland Islands, Antarctica) during 1991/1992 to 2002/2003 campaigns have characterized the deformation of the island resulting from its volcanic activity. From January 1992 to December 1999, radial extension together with an uplift episode was detected. During this period two important episodes of seismic activity took place, in particular, during the campaigns 1991/92 and 1998/99. From 2000 until 2003, no large displacements were detected, although the stations seem to converge in a radially compressive manner together with a subsidence, reflecting a change in the geodynamics of the island. Two clear alignments are observed on the contour maps that characterize the deformation, one in the NW-SE direction until 2000 and another on in the NE-SW direction from 2000 to 2003, coinciding with the principal directions of the tectonic features of the region, the Hero Fracture Zone and the Bransfield Rift.