Analisis de los registros magneticos de la Isla Decepcion. Correlacion con la actividad volcanica

After the increase of the seismic activity detected during the 1991-1992 summer surveys at Deception Island, the continuous measuring of total magnetic intensity was included among the different techniques used to monitor this active volcano. The Polish geomagnetic observatory Arctowski, located in King George Island, served as reference station, and changes in the differences between the daily mean values at both stations were interpreted as indicator of volcanomagnetic effects at Deception Island. A magnetic station in continuous recording mode was also installed during the 1993-1994 and 1994-1995 surveys. During the latter, a second magnetometer was deployed in Deception Island, and a third one in the vicinity of the Spanish Antarctic station Juan Carlos I in Livingston Island (at a distance of 35 km) and was used as reference station. The results from the first survey suggest that a small magma injection, responsible for the seismic re-activation, could produce a volcanomagnetic effect, detected as a slight change in the difference between Deception and Arctowski stations. On the other hand, a long term variation starting at that moment seems to indicate a thermomagnetic effect. This effect finishes towards the end of January 1994, as suggested by the recovery of an almost constant difference between both stations, which is also detected with respect to Livingston Island during the 1994-1995 survey. The future deployment of a magnetic array during the austral summer surveys, throughout the volcano, and of a permanent geomagnetic observatory at Livingston Island is aimed to further observations of magnetic transients of volcanic origin at Deception Island.