A Combined Velocity Field of the Mediterranean Region

We provide a new 3-D GPS velocity field solution of the Euro-Mediterranean area computed at the Centro Nazionale Terremoti (CNT) division of the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The available raw GPS data since 1993, have been fully reprocessed by three different software and the final velocity field is obtained by combining three independent velocity solutions in a least squares sense. The input velocity solutions are treated as stochastic samples of the true velocity field by loosening the reference frame constraints in the associated variance-covariance matrix. The proposed approach allows for a fast combination of multi velocity solutions taking into account the full covariance, if available. The velocity map for the Euro-Mediterranean region will be updated and released regularly on the web portal of the National GPS Network (http://ring.gm.ingv.it). Here we show and discuss in detail the data analysis, combination scheme and results of the analysis procedure.