A new approach to model the kinematics of crustal deformation with applications to the Aegean and Southeast Asia

Abstract

An important factor in the study of lithospheric deformation is an accurate representation of the kinematics of the Earth's crust. This thesis presents a new inversion method to model the present-day kinematics of the deformation field of the Earth's surface by the use of (space) geodetic measurements of relative motion. The aim of the method is to represent the kinematics of the crustal deformation field without implicitly relating kinematics to the style of deformation at depth and without restrictions about the spatial scale of the region under consideration. The method inverts relative motions between all pairs of stations of a particular velocity data set (in this thesis mainly GPS data), in a regularized least-squares approach, for the velocity gradient field in crustal blocks and for fault motion on the active faults or block boundaries. The method is applied to a synthetic velocity field and to data sets obtained in the Aegea and at Southeast Asia. The results from the synthetic application are promising: The data are fit within their error bounds for solutions that result in a good model fit, are well resolved and have acceptable covariance. In general, the results from the application to the Aegean data are in good agreement with paleomagnetic, geodetic and geologic observations. This conclusion suggests that the deformation field reflects larger-scale crustal block motion. A new, detailed view on the present-day kinematics of the Aegean crustal deformation field is presented. The results from the application to a combination of GPS data sets obtained in Southeast Asia demonstrates that inverting for velocity gradient and fault motion simultaneously enables the accommodation of localized motion on faults or plate boundaries and offers insight in the distribution of relative plate motion in plate boundary zones in terms of slip, (micro-)block rotation and strain rates.