Combined seismic and geodetic experiment at volcanic zone in northern Chile. Location is near active volcanoes Azufre and Lastarria at -25.15S -68.30W in an area increased ground displacement. From January until April 2007 a network of 12 BB stations will be set up together with 6 GPS and 2 extensometers. Joint analysis of these data will allow to locate magmatic sources and to determine physical volcanotectonic processes.