Is the motion of the Eastern Mediterranean region faster than expected?

Abstract

AbstractThe horizontal motions of the lithospheric plates generally range from a few millimetres to more than 150 mm/year; smaller motions are expected in the vertical direction. The measurement of such small relative movements has been made possible by the development of satellite geodesy [satellite laser ranging (SLR) and the global positioning system (GPS)] followed by very long baseline interferometry (VLBI). It is now possible to measure motions of less than a few millimetres per year from space.To monitor the relative movements in the Eastern Mediterranean region, SLR measurements to the LAGEOS satellite have been made within the WEGENER MEDLAS Project (Working Group of European Geoscientists for the Establishment of Networks for Earth Science Research Mediterranean Laser Ranging) since 1986 on four platforms in Turkey: Bolu/Yigilca [on the north side of the North Anatolian Fault (NAF)], Yozgat, Karaman/Melengiclik and Diyarbakir (on the Anatolian plate) as well as on six additional sites in Greece. The first results of the measurements made in 1986, 1987 and 1989 support earlier seismic results. The results from the SLR campaigns indicate a right‐lateral motion across the NAF. The results of two GPS campaigns carried out in 1988 and 1990 in north‐west Turkey indicate similar movements.The NAF shows a right‐lateral movement of 25 mm/year and the north‐western part of the Anatolian block escapes south‐west at a rate of 50 mm/year; more than expected.Up to the studies of Oral et al. (1992), the results of the vertical motions of the SLR and GPS campaigns coincide and show a surprisingly high rate for the station on the Anatolian peninsula of about 5 cm/year downwards.