Geophysical research: article

D. Abramova1
L. Abramova2
I. Varentsov2
S. Filippov1
1 Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences
2 Geoelectromagnetic Research Centre, Shmidt Institute of Physics of the Earth, Russian Academy of Sciences
Journal: Geophysical research
Tome: 20
Number: 2
Year: 2019
Pages: 5-18
UDK: 550.34.09
DOI: 10.21455/gr2019.2-1
Full text
Keywords: satellite measurements, lithospheric magnetic anomalies, Greenland-Iceland-Faroe ridge complex (GIFRC), spreading, mantle plume, old continental crust
Аnnotation: The distribution of the field of regional lithospheric magnetic anomalies above the Greenland-Iceland-Faroe ridge complex (GIFRC) which is part of the North Atlantic igneous province, one of the largest magmatic provinces in the world, is analyzed. The data were obtained from measurements of geomagnetic field made by the low-flying German CHAMP satellite, when its altitude significantly decreased. To isolate the part associated with the field of lithospheric magnetic anomalies, a special original technology of separating the field parts from the total volume of the CHAMP satellite records determined by the presence of deep sources of regional anomalies was developed. Database of experimental data of the absolute induction vector module Ta of the anomalous lithospheric magnetic field at satellite altitude was created. Maps of different scales for the anomalous lithospheric magnetic field at an altitude of 280 km above the Greenland-Iceland-Faroe ridge complex were constructed. In their construction, various types of median averaging blocks of size 80´80 km and 10´10 km by means of GMT were used. The relations between the identified lithospheric magnetic anomalies with the structures of the studied magmatic province and the active tectonic processes occurring in it up to the present day were discussed. The vast area of negative values of the anomalous magnetic field, observed at an altitude of 280 km, reflects the superposition of the spreading of the Mid-Atlantic Ridge and magmatic processes occurring in this zone, not only directly along the axis of the ridge, but also along its peripheral branches. The traced positive magnetic anomalies, apparently, fix the presence of separate fragments of the ancient continental crust, submerged under the powerful structures of the basaltic base. The maps of the anomalies of T