Developing a High-Resolution Subsurface Model through Teleseismic Wave Simulation in Hamburg

We aim to simulate the wave propagation in the complex near-subsurface in urban environments. Here, we focus on the DESY and physics campus with its large underground accelerator tunnels in Hamburg, Germany. Since these particle accelerators, and other sensitive physics experiments on campus, are sensitive to seismic vibrations, it is important to understand how the seismic wavefield couples into the building structures.

To achieve this, there is a need to develop a high resolution subsurface model of Hamburg region. However, to model the whole seismic wave path in 3D for teleseismic events is computationally expensive. In order to circumvent this issue, the present work explores using RegHym package for earthquake simulation of teleseismic events. This package combines the efficiency of Axisem and flexibility provided by SPECFEM3D to embed the intricacies at regional scale in the model. This allows to simulate wave propagation for a teleseismic event on a regional scale in a computationally less-expensive way. 

We are exploring the package to broaden its usability to model full waveforms of tele-seismic events for Hamburg area, incorporating the complex geological and urban environments. The subsurface model will be refined through consecutive comparisons of the synthetic data with data available from a DAS network implemented at the DESY campus in Hamburg. The real data from DAS will be enriched by incorporating recorded data from seismometers deployed in the vicinity of the DAS network.

The refined model will be a fundamental step for numerically investigating the coupling of incoming seismic waves into urban infrastructures as well as into gravitational wave observatories, which are sensitive to very small seismic disturbances.