Publication Date:
2017-04-04
Description:
GEOSTAR, an European-funded project, is based on a submarine multidisciplinary
observatory, that gathered geophysical and geochemical data during a period of six
months, from September 2000 to March 2001, in its first deep seafloor mission (about
2000 m depth), off the coast of Ustica Island (Sicily, Italy). GEOSTAR was equipped
with several scientific instrumentations, among them two magnetometers. Total
intensity of the Earth’s magnetic field and its vectorial components were recorded by
means of a scalar magnetometer (Overhauser type) and a suspended three axial
fluxgate magnetometer, the latter being designed and built at the Istituto Nazionale di
Geofisica e Vulcanologia laboratories. The adverse conditions of an environment
located at 2000 m under the sea surface, obliged the making of a special design for the
whole frame, including the use of non-magnetic materials for the structure, and the
installation of two opposite expanding arms that contained the magnetometers. The
geomagnetic experiment was completed by carrying out two fundamental procedures:
the instrumental calibration and the computation of the vectorial magnetometer
orientation with respect to the geographical reference, both are described in this paper.
We also illustrate some properties of the complete magnetic data set, together with a
spectral analysis performed in a particular condition of planetary magnetic activity, as
well as applications aimed at extracting information about the crustal electric
conductivity from the magnetic data in the area around Ustica Island.
Description:
Published
Description:
105-114
Description:
open
Keywords:
geomagnetic
;
GEOSTAR,
;
01. Atmosphere::01.01. Atmosphere::01.01.08. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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