JOURNAL OF THE BALKAN GEOPHYSICAL SOCIETY, Vol. 2, No 3, August 1999, p. 84-89, 4 figs.

Mujgan Salk

Dokuz Eylul Universitesi, Muhendislik Fakultesi, Jeofizik Bolumu, Bornova, Izmir-Turkey

E-mail: msalk@ izmir.eng.deu.edu.tr

( Received 4 February 1999; accepted 20 March 1999 )

Abstract: NASA launched the magnetic field satellite, MAGSAT, to examine specifically large- and medium scale lithospheric anomalies. The data measured by Magsat have been used to study the distribution of crustal magnetisation in an area between 25° - 45° E longitude and 35° - 45° N latitude. Magsat maps were prepared by extracting the external and main field from the measured data. The data interpretation is performed in view of a magnetisation model in which the Earth' s lithosphere beneath Turkey is subdivided into blocks having dimensions of 2° in latitude and longitude. Each block is represented by a dipole as being parallel to the main core field. The model parameters are updated by an iterative scheme until a reasonable fit between the theoretical data and the model response is obtained. A method that produces an approximation to a crustal magnetisation distribution from the inversion of satellite magnetic anomaly data is described. The method consists of an equivalent source representation of the observed anomaly field. The application of the method to the Magsat data indicates that positive magnetisation values dominate eastern and western Turkey. Negative magnetisation values are observed in the Black Sea. The low amplitude magnetisation anomalies may be related to a relatively shallow Curie isotherm that reflects high rate of heat flow.