Marine magnetic survey across the Western Scotia Plate

LIPPAI H. F.; TASSONE, A; LODOLO, E; VILAS, J. F,

Buenos Aires

Conferencia; SCAR XXXI. .4 th Open Science Conference; 2010

Dirección Nacional del Antártico

The generation of the western Scotia plate (WSP) at about 30 Ma led to the separation of the South American (SA) and Antarctic plates (AP). A series of transform faults normal to the ridge accommodated the opening movements and displaced the volcanic blocks. Within the WSP there are segments that have not been studied. Recently a magnetometric survey was carried out on board of the oceanographic ship CONICET-Puerto Deseado, crossing the WSP from Tierra del Fuego in the north to the zone of Orkney Islands to the South, between W3 and W4 opening corridors. The magnetic data were acquired along 3 profiles with a total length of about 624 km. A marine magnetometer Geometrics G882 SX of Cesium steam (sensitivity of 0,004 nT/Hz) was employed which allowed the acquisition of 10 samples per second with an absolute precision of ± 1 nT. The magnetometer was programmed for a sampling speed of 1 value every 3 seconds, which resulted in a sampling distance of 12.28 m and a total of 56207 data. Data were recorded with the program Mag Log and data reduction was done with the Magmap 2000 software. Two pairs of GPS Trimble & Fugro allowed the continuous DGPS of sampling profiles. The collected data have been correlated with other profiles of our data base and those reported in bibliography to generate a detailed map of the magnetic anomalies related to the opening of the of these WSP segment.