Abstract

With the rapidly increasing amount of seismic data available from large seismic broadband experiments such as the AlpArray and AdriaArray networks, new methods need to be invented to fully utilise the high resolution capabilities of such dense, regular arrays for seismic tomography.Our experiments focus on the structure of deep orogenic roots, such as those of the Alps and neighbouring orogens, for which the signals of distant seismic earthquakes are required. We developed tools for the precise automatic determination and inversion of the first arrivals of those teleseismic signals that were recorded by AlpArray between 2015 and 2019. We show the evolution and results of recent teleseismic upper-mantle tomographic studies at the University Bochum starting with a travel-time tomography (TTT) that uses a sophisticated cross-correlation algorithm for first-onset determination and a new method for crustal model integration. We continue with a full-waveform inversion (FWI) that uses an advanced source-time function calculation and a new 3D hybrid forward solver and is able to resolve upper-mantle and even crustal velocity anomalies in enormous detail. Finally, we show an outlook on how a possible combination of both methods could unite their advantages and present a “true” blind-testing approach for the TTT by inversion of residuals picked from the synthetic waveforms calculated by the FWI forward solver.