Analysis of total crustal deformation by the comparison of terrestrial and GPS measurement in the Marmara Region

Abstract

In order to monitor crustal movements along one of the branches of North Anatolian Fault Zone (NAFZ), Geodesy Department of Kandilli Observatory and Earthquake Research Institute (KOERI) established microgeodetic networks around the eastern Marmara Region. General Command of Mapping (GCM) - Istanbul Technical University (ITU) net as part of the networks was measured from 1941 to 2007 five times with both space methods and conventional methods. The terrestrial network implemented by GCM as constitution of nine pillars scattered around south and north of Iznik Mekece fault. The net was measured by trilateration and triangulation methods by GCM and ITU. After KOERI Geodesy Department joined GCMITU net in Marmara Microgeodetic Project, the net was also monitored by GPS Campaigns. This study is based on the use of repeated observations over the network and on the analysis of the results obtained from different epochs by means of displacements. Thus, first all epoch of observations were computed and then the amount of displacements were analyzed judging by the fault movement and the accuracy values for each observation method. In addition to this, in order to check the coherence of results, GPS campaign data have been processed in detail.