In April 2020 a conventional VSP survey was conducted in a geothermal well in the Munich metropolitan area, Germany. At the location a second well was equipped with a fiber optic cable installed until reservoir depth at 3691 m (MD) (Schölderle et al,. 2021). Along this cable, distributed dynamic strain sensing data (also known as Distributed Acoustic Sensing, DAS, or Distributed Vibration Sensing, DVS) was acquired piggiback. The here published dataset comprises the 16 s long raw DDSS recordings framing 419 12 second long vibro shots emitted from two different locations (one near vertical and one at 1 km distance), the respective sweep functions, the coordinates of the shot locations and the receivers relative to the wellhead, and the stacked correlated records. Absolute coordinates were anonymised.
The lithosphere-asthenosphere boundary (LAB) marks the base of the Earth’s outer layer where heat is transferred primarily by conduction as compared to prevailing convective heat transport below. Spatial variations in LAB depth reveal the differential evolution of tectonic systems (e.g., rifts and orogens), thus enabling a better understanding of geodynamic processes. Further, the topography of the LAB exerts control on the coupling of the lithosphere to asthenospheric flow, modulating the distribution of present-day stresses and active deformation of the tectonic plates. We have derived global depth variations of the LAB from temperature-converted shear-wave tomography models assuming that the threshold temperature between conduction and mantle convection is 1300 °C. Shear-wave velocity in the mantle is controlled by both in situ pressure-temperature conditions and mineralogical rock composition. Therefore, our velocity-to-temperature conversion builds on a framework of rock physical properties generated through a Gibbs free energy minimization to determine thermodynamically stable phase and mineral assemblages throughout upper mantle pressure and temperature conditions. In this data publication, we provide thermal LAB depths corresponding to one European-scale and three global-scale tomography models. The data release includes (i) a data description file with information on the input tomographic models, the conversion method and spatial variations in LAB depth (illustrated); and (ii) four data files with LAB depth values spatially sampled according to the input tomography models.