The geophysical characteristic of the lower lithosphere and asthenosphere in the marginal zone of the East European Craton

Abstract

Seismic P-and S-wave velocities of the lower lithosphere and underlying asthenosphere at the SW margin of the East European Craton in northern Poland were obtained with different seismic techniques: seismic refraction, P-residuals of the first arrivals from teleseismic earthquakes, P-wave receiver function, and inversion of the Rayleigh surface wave dispersion curves, the last two using data collected in the passive seismic experiment "13 BB star". The uniform array consisted of 13 stations deployed in a 120 km in diameter area. Below the depth of 180-220 km a decrease of about 6% of the S-wave velocity is interpreted as a thermal gradient zone corresponding to a lithosphere-asthenosphere transition. The average mantle velocities down to a depth of 300 km beneath the array are relatively high, exceeding values for other Precambrian cratons by 0.1-0.2 km/s, and cannot be modeled by reasonable mantle peridotite compositions in the lithospheric part of the profile. We suggest that significant peridotite anisotropy could explain the misfit between measured and calculated seismic velocities in the lithosphere.

Thermal properties of the crust and the lithosphere–asthenosphere boundary in the area of Poland from the heat flow variability and seismic data

“…"Priestley" map is extracted from global seismic LAB map (Priestley and McKenzie 2013). "Seis-Grav" map is com-piled from regional seismic LAB data (blue dots), compiled from Wilde-Piórko et al 2010, Geissler et al (2010), Grad et al (2015Grad et al ( , 2018, and from gravity LAB data (red dots), compiled from Bielik (1999), Horváth et al (2006) and Grabowska et al (2011) receiver function (Geissler et al 2010), dispersion of surface waves (Grad et al 2018). Gravity LAB depths were compiled from 2D gravity modeling (Bielik 1999;Bielik et al 2006;Grabowska et al 2011) and from regional map (Horváth et al 2006).…”

Reliable workflow for inversion of seismic receiver function and surface wave dispersion data: a “13 BB Star” case study

“…As mentioned in Section 4.2, e.g., Meier et al (2016) applied an automated procedure of data selection (e.g., constraints on the smoothness), which might have rejected the data illuminating local structure on a finer scale. For a detailed discussion of the geophysical properties of the lithosphere in this area, see Grad et al (2018).…”